OpulenZ: new logo, some refactoring.
Added two standard paths to file open/save dialog

In particular Desktop and Downloads have been added.
Also introduced a new function to create a file dialog
in order to prevent code duplication.
Merge https://github.com/LMMS/lmms into stable-0.4

Conflicts:
	plugins/opl2/logo.png
Added pitch bend
Loop marker: Changed tooltip text.
Update timeline.cpp
MainWindow: Moved FileDialog to own subclass
Update code to use FileInfo instead of QFileInfo

Also removed all blocks similar to
```
#if QT_VERSION >= 0x040806
	filedialog.setOption( QFileDialog::DontUseCustomDirectoryIcons );
#endif
```
as this now takes place in the new subclass's constructor.
Add new class VersionedSaveDialog

A file save dialog (inherits FileDialog) that provides buttons to
increment or decrement a version which is appended to the file name.
(e.g. "MyProject-01.mmpz")
Add "Save as new version" action to project menu

Use Shortcut Ctrl+Alt+S. Part of issue #86
Make LFO controller accept custom waveforms
Tooltip: Changed tooltip text of LFOControllDialog of custom waveform
Merge https://github.com/LMMS/lmms into stable-0.4

Conflicts:
	plugins/opl2/opl2instrument.cpp
Merge https://github.com/LMMS/lmms into stable-0.4
About window: Make homepage link clickable
About window: Update copyright year to 2014
#67: Add list of all committers to about window
Travis: Set build mode to RelWithDebInfo

This may lead to build errors, as variables that are only used in asserts
will get optimized out and because of -Werror being set (unused variables).
OpulenZ: added velocity & aftertouch, cleaned up some unneeded code
Fix some warnings