LmmsStyle: initial port of scrollbar drawing code from CusisStyle

Colors still need to be made configurable via CSS and tuned for the
default theme.
LmmsStyle: adopted new coding style and renamed class
pitch automation in piano roll doesn't require first point to be 0
points are shown in the correct scale
draw discrete and linear differently
Merge pull request #41 from grejppi/stable-0.4-pitchautomation

WIP: Pitch automation improvements in Piano Roll
Prevent piano roll window from being resized to 0px height (http://sourceforge.net/p/lmms/patches/43/)
Merge pull request #45 from grejppi/stable-0.4-pianorollresize

Prevent piano roll window from being resized to 0px height
Merge branch 'stable-0.4' of github.com:LMMS/lmms into stable-0.4
FxMixer, FxMixerView: cache maximum peak until next display update

We lost short peaks because the display update rate usually is much lower
than the number of audio buffers processed per second which lead to lost
peaks. We mitigate this issue by caching the maximum peak value until the
next display update where it is reset.
FxMixer: ignore mute state in addChannelLeaf() to fix lockup

Even if we do not process the FX chain later, we at least have to enqueue
all related FX channels to the job queue in order to prevent a lockup.
Merge branch 'stable-0.4' into stable-0.4-new-fx-mixer

Conflicts:
	src/core/FxMixer.cpp
	src/gui/FxMixerView.cpp