InterruptReminder 

Release 1.2.0
Bug fixes:
1. Add-on will not get blocked anymore for trying to access blocked functions through the usage of LibButtonGlow-1.0
2. When switching to a new target, it will now check if the target is in the process of casting and proceed to act accordingly
3. If the player had multiple interrupts on his action bars, in some cases, the wrong button would get highlighted.

New addition:
1. Now able to capture spells that are currently on cooldown and pass them to a callback handler. If the spell becomes available before the target's spellcast finishes, the ability will get highlighted.

General changes:
1. Made all functions related to the add-on local rather than global
2. Optimized the code to run more efficiently where possible
3. Added documentation (for my own sanity)

Release 1.2.1
Bug fixes:
1. Fixed bug where an NPE would be raised if the player did not have one of the interrupts unlocked on his character (oops)
2. Fixed a bug where interrupt handling would occur on friendly units (no highlights would occur still)

Release 1.2.2
Bug fixes:
1. When the target gets crowd controlled, the spell would stay highlighted
2. When the target loses sight of player, the spell would stay highlighted
3. If the target was channeling, the spell highlight would sometimes appear and disappear in a span of a second

General changes:
1. Rewrite on how the events are handled inside OnEvent (to avoid duplicate code)
2. More documentation

Release 1.3.0
New Addition:
Added the ability to track Crowd Control spells as well using an algorithm to find all spells capable of inflicting a crowd control status effect. With that, also added several slash commands as well as a bunch of internal functions to determine whether the current target can be affected by a crowd control spell.
General Changes:
Due to the optional support of Crowd Control spells, most of the add-on logic had to be rewritten from ground up.
Bug Fixes:
Fixed a bug where moving an interrupt spell to another location would cause the glow effect to stop functioning correctly.

Release 1.3.1
Bug Fix:
Fixed a bug where Evoker's Breath of Eons would be one of the highlighted spells
Fixed a bug where invalid targets casting spells would still cause the add-on to act

Release 2.0.0
New Addition:
Options page! All backslash commands except for /irinfo have been removed and migrated to a per-character options page.
The player can now select individual spells that should be highlighted when an interruptible spell is being cast by the target.
Bug Fixes:
Fixed a bug where off-cooldown spells that are eligible to be highlighted just didn't highlight. Issue had to do with the data returned by GetSpellCooldown().

Release 2.0.1
New Addition:
Support for ElvUI. Should work the same as WoW's default interface.
Caching of action button locations for faster repeat access.
Improved algorithm that finds extraneous spells for faster search.
Bug Fixes:
Fixed Mage Counterspell not appearing in the options menu.
Fixed nil exception when selected spells are empty.

Release 2.1.0
New Addition:
Highlight configurator! Can now select different configurations for the highlight of spells.
Three new highlight types for the spell highlight effect.
New library to handle the highlighting of spells.
General Changes:
Frontend optimization where possible and fixing some race conditions in the frontend.
Proc is now the default highlight style.

Release 2.1.1
General Changes:
Removed Quaking Palm from the Monk class as it is a Pandaren racial skill.
Added new slash command /irconfig to quickly access the options menu.

Release 2.1.2
General Changes:
Updated interface version

Release 2.1.3
General Changes:
New Icon

Release 2.1.5
Bug fix:
Fixed missing library error, LibFramePool-1.0.