Added Init() to TOOL_INTERACTIVE, allowing to set up things that are needed to be initialized only once.
TOOL_ACTIONs can be run from CONTEXT_MENU after adding them.
Move tool actions are available to be run from CONTEXT_MENU displayed after right mouse button click on selected items.
Added some asserts to check the code.

Less objects are allocated dynamically.
CONTEXT_MENU is being run using its copy (it saves a hassle of following the lifetime of object).

Added rotate & flip to the pcbnew.InteractiveMove tool, hotkeys for them and undoing all the  operations on cancelling the tool.

FIxed TOOL_EVENT::Modifier() (now it returns value for current modifier, not only if there is one active or not).

Pcbnew: better dialogs to select the active layer or a layer pair. Add an option (hotkey+popup menu) to place a via and select the new active layer
(useful for boards having more than 2 layers)
Eeschema:fix compatibility with old schematic files, when they  contain ERC markers.
Pcbnew: better test for allowed layers when creating/editing Dimensions and some other Graphic items
Drc:  fix comments and messages for some drc tests.
Fix minor bugs in cleanup dialog options and plot solder mask function (thanks to Lorenzo to locate these bugs)

Removed TA_ActivateTool (now tools are invoked by sending TA_Action event, with the tool name as string parameter).
Developed TOOL_Action class & added ActionManager. Hot keys registered by tools are processed.
Selection & move tool can be invoked by a hot key.

Fix minor bugs in cleanup dialog options and plot solder mask function (thanks to Lorenzo to locate these bugs)