Warnings & migration informations
This is a beta. Because there are more than 30'000 lines of code that has changed, precaution must be taken. Make a backup before upgrading. Try this version on a development server before the production one. Extensions will break (BeautyQuestsAddon for instance, but I'm working with its author to update is quickly).
Once you've upgraded to 1.0, you cannot go back to 0.20 or 0.21.

I did my best to make all migrations happen automatically, but some points of caution must be taken:

• some strings will look weird, because of the placeholders system that has changed. Your best bet is to completely delete the /plugin/BeautyQuests/locales directory before upgrading.
• because you can now have multiple NPC plugins, the format in which the npc ids are stored has changed. Migration should happen automatically, but you may have some warnings in console if NPCs are nowhere found.
• as stated further down, the skillAPIoverride option has been deleted. If you've been using it, you must therefore replace your "vanilla" XP rewards with the new SkillAPI XP reward.
• many options in config.yml have been renamed or moved. It should happen automatically but... who knows? Backup config.yml as well!

Changelog
Code-wise:

• Completely separated the api, the features and the integrations in different modules. This will help future development, and will make extension development easier for external developers.
• Rewritten most of the plugin to allow more flexbility in future features. This means cleaner code, less bugs and hopefully a performance boost!
• Deployed javadocs and sources artifacts of the API on the Maven repository

NPCs integrations:

• Having an NPC plugin is no longer mandatory to use BeautyQuests This means anybody can now simply download the plugin and run it without any dependency to add.
• You can now have NPCs from multiple NPCs plugins. For instance, some of your NPCs come from Citizens, and some others from ZNPCs. Changed how most stages handle progress:
• all stages that have some kind of progress can now have a progress bar (e.g. "eat food", "craft items" or "play time")
• you can now configure much more finely the description of stages with progress in config.yml
• added integration for ZNPCsPlus (both pre-2.0 and post-2.0)
• upgraded support for ZNPCs from 3.6 to 4.2

Placeholders:

• All placeholders in strings are now named and no longer indexed.
• For instance: Level {short_level} for {job_name} replaced Level {0} for {1}
• This is 1. much more easier to understand when translating the plugin
• And 2. an amazing thing to allow much more personalized messages, because there are now many different placeholders for every message.

Rewards/requirements

• By popular request, the remove button for rewards and requirements from middle-click to shift + left-click
• Added a way to configure the reason sent in the chat when a player wants to start a quest but does not meet a requirement
• Added a way to configure the description of rewards and requirements in the quest description shown in the menu
• Fixed issue with requirement reason order

Quest selection:
Reworked quest selection GUI (the menu that appears when a player clicks on an NPC): the description, rewards and requirements of quests are now shown. It is also now more configurable:

Code (YAML):

# - Quest selection -

# Options related to the behavior when a player click on an NPC which has associated quests
questsSelection :
  # If enabled, the "choose a quest from this NPC" GUI will not open if there is only 1 quest attached to the NPC
  skip gui if only one quest : true
  # Hide quests from the GUI if the requirements are not met
  hide quests without requirement : true

Misc. changes:

• The GPS integration has been removed and is now a tracker in the expansion
• The skillAPIoverride config.yml option has been deleted. Instead, a new reward type has been created: "SkillAPI XP Reward"
• Placeholders are now parsed by default in command rewards
• Checkpoints are now using the "quest flow" feature to follow the path players have taken during the quest
• Changed middle-click to shift-left-click to remove items from GUIs
• Added %beautyquests_quest_restartable_ID% placeholder to get whether a quest is restartable or not
• Added support for 1.20, 1.20.1 and 1.20.2
• Added MMOItems item comparison
• Fixed multiple exceptions
• Fixed an issue with the "parse placeholders" option of "write in chat" stage not working
• Added "max messages per history page" dialog option in config.yml
• Changed some quest pool give logic, this will probably fix issues with the "avoid duplicates" pool option. This will also allow users to use the "yes/no" GUI to accept or not quests from the pool!