Song: use Kicker as default instrument in B+B-Editor

Using TripleOscillator as default instrument in B+B-Editor doesn't
make much sense so use Kicker instead.
DetectMachine.cmake: do not use lib64 as LIB_DIR anymore

Installing to $prefix/lib64 is not usual anymore and thus we change it here
to just install all libraries to $prefix/lib.
Fix import of 32-bit floating point samples
Merge pull request #14 from diizy/fix32

SampleBuffer: fix import of 32-bit floating point samples
adds piano_roll key presses
Merge branch 'stable-0.4' of https://github.com/bhattigurjot/lmms into stable-0.4
TrackContainer, TrackContainerView: adopted coding style

Renamed file and class names.
SampleBuffer, SamplePlayHandle, SampleRecordHandle, SampleTrack: new coding style

Renamed file and class names.
Merge pull request #17 from bhattigurjot/stable-0.4

PianoRoll: added support for pressed keys
Piano: refactored class to be usable without friend classes
PianoRoll: coding style improvements
Added volumeToMidi() helper function
Piano: added optional velocity argument to handleKeyPress()
PianoRoll: always use the PianoModel for note on/off + other improvements
PianoRoll: fixed typo leading to big white key at wrong position when pressed
New SF2 plugin artwork
Final tweaks to SF2 artwork (based on feedback), moved chorus & reverb buttons a bit to fit them better with new artwork
New led graphics, initial style sheet changes (work still in progress), other theme changes