ZynAddSubFX/FLTK: fixed detection of freetype2 include path once more

Commit 26665dde55cfa589f166998ea587db70cd516b68 was not complete as we have
to find the Freetype package and also look for freetype2 include path.
AutomatableModelView/ContextMenu: option for unlinking all controls

Integrated patch by Rodrigo Rodrigues da Silva which adds an option
to all AutomatableModelView's context menu allowing to unlink all
linked controls.
AutomatableModelView: adopted new coding style
config option to enable waveform display by default
Merge pull request #30 from softrabbit/stable-0.4

PianoRoll: fix odd time signature issues (bugs 274 and 172 at SF)
Merge pull request #31 from grejppi/stable-0.4-displaywaveform

config option to enable waveform display by default
Merge pull request #1 from LMMS/stable-0.4

pulling changes