Moved background color settings from GAL to RENDER_SETTINGS. Added RENDER_SETTINGS::TranslateColor() to convert between EDA_COLOR_T and COLOR4D.

Most of the changes are just adding GetDesignSettings() before every occurence of m_NetClasses.
More complex changes:
class_netclass.cpp - NETCLASS does not store the pointer to the parent BOARD anymore. Added function SetParams( BOARD_DESIGN_SETTINGS& ).
class_netclass.h - Removed GetTrackMinWidth(), GetViaMinDiameter(), GetViaMinDrill(), GetuViaMinDiameter(), GetuViaMinDrill() as they were refering to BOARD_DESIGN_SETTINGS anyway (they are not net class specific).
kicad_plugin.cpp - filters out empty nets (that are anyway not saved) when storing net class information. Previously it was done in NETCLASS::Format() function.

Moved a few one-liners of BOARD_DESIGN_SETTINGS class to the header file.

Moved menuCopy to CONTEXT_MENU copy constructor.

Cursor position is saved as a field in order to avoid drifting of items while they are being dragged and rotated/flipped.

Added WX_UNIT_TEXT - wxWidget control for inputing sizes using different units (mm, inch, internal units).

Resolved HOME hot key conflict between menu entry (Zoom Page) and event assigned to the hot key in the ACTION_MANAGER.
Conflicts:
	pcbnew/menubar_pcbframe.cpp

Added preference for selecting tracks/vias/graphics if there is a module present in the selection point.