Update README.md
Update Linux builds for 0.5.4
Merge pull request #101 from morevnaproject/master

Update Linux builds for 0.5.4
Temporary tools: event conflicts prevention

1. prevent fixed shortcuts to be executed while drawing
2. temporary tool will not return to previous state until both mouse and
shortcut keys are released
Merge pull request #102 from eVoLuTiVeMEDIA/master

Event conflicts prevention (for fixed shortcuts including temporary tools)
Resolve conflict
some undo issue preventions (clearImage & deleteSelection)

1. Prevent from unnecessary updates
2. Prevent from extra undo backups
3. Optimised if-else
Add keyframe struct
Add keyframe class
Add camera class in its own file
Add keyframe helper methods to Layer.cpp

I think we should move all the keyframe stuff to layer to avoid casting
Add scrubNextKeyframe and scrubPreviousKeyframe methods
Fix interesting bug in scribblearea when pressing keys?

couldn't really reproduce consistently
Add previous and nextkeyframe actions to the menu
Merge pull request #108 from eVoLuTiVeMEDIA/master

Some undo issue preventions for clearImage & deleteSelection
Merge pull request #110 from wesen/feature/navigate-drawings

Navigate to previous and next keyframes with < and >
Resolve conflict
resolve conflict
Merge branch 'feature/color-picker' of https://github.com/chchwy/pencil2d into feature/color-picker