Bumped version number to 1.0.91

We can now distinguish between the new stable 1.1 branch and the master branch.
Merge pull request #776 from xsleonard/cut-copy-paste

Copy+Paste for rubberband selections in track editor
Initial implementation of sample-exact models and controllers
Also featuring a very efficient buffer-based system for transporting sample-exact control data
Also interpolation for automations
The native Amplifier is a reference implementation for taking advantage of sample-exact data and is currently
the only one that does so, it can be used to test things out, and as documentation/example for implementing the
same elsewhere
Move improvements to sample-exact controller handling,
also some coding style fixes
LfoController updates - fix some remaining timing issues
Models: Fix error
PianoRoll: CSS stylability
Most parts of piano roll are now stylable:
- background color
- note color
- bar color (for volume bars)
- grid color
AutomationEditor: improve zoom functionality
- entire wheelevent code was written very... weirdly, I simplified it
- fix bug with x zoom with mousewheel, no more getting stuck between 25/50
- ctrl+shift+mousewheel now zooms y-axis
- ctrl+alt+mousewheel now changes quantization
AutomationEditor: CSS stylability
AutomationEditor - fix previous
PianoRoll: wheelevent improvements, similar to AutomationEditor
- ctrl+alt+wheel changes q (as in auto)
- ctrl+shift+wheel changes note length
- changed note lock functionality slightly, it no longer changes itself to 1/16 because this would cause annoying infinite scrolling with the wheel, instead it just acts like 1/16 when notelength is last note
Merge pull request #792 from diizy/autoeditor

AutomationEditor: improve zoom, CSS
Merge pull request #789 from diizy/pianoroll

PianoRoll: CSS stylability, mousewheel improvements
Merge pull request #788 from diizy/models

Models branch for 1.2
InstrumentTrack: Fix issue #780 by showing the m_pitchRangeSpinBox too, in case it's been hidden.
S.ex. models: implement support for sample-exact controls in fx-mixer
Works for all faders and send knobs
Merge pull request #797 from softrabbit/issue780

Issue780
FxMixer, ValueBuffer, etc. fixes
Merge pull request #799 from diizy/models3

S.ex. models: implement support for sample-exact controls in fx-mixer
Fix Instrument LFO, random wave icon