SymbolTool (OPTION A)

OPTION B: !4984 (closed)

Allow paint with symbols.
Uses:
Speed up adding symbols
Heads up symbols
Paint in a concept-art way to produce fast draws (mostly backgrounds)
Allow to paint symbols directly colorizing it in 2 clicks (change color and add)
Keep last used symbols available even when change document in symbols dialog
...
Improvements
Allow LPE on symbols, persistent on unlink or when using path mode
Allow use between symbols documents gradient, style tags/clases, filters (defs objects)....
Lots of fixes on symbols behabiour