Fix RThread.cpp build failure

RThread.cpp: In static member function ‘static QString RThread::currentThreadAddress()’:
RThread.cpp:52:60: error: cast from ‘QThread*’ to ‘int’ loses precision [-fpermissive]
make[3]: *** [release/RThread.o] Error 1
fix FS#965 - Modify - reverse: fails for imported splines
Merge branch 'master' of github.com:qcad/qcad
update
fix FS#967 - SVG import: SVG transformations can lead to wrong arc directions

make transformation API using QTransform available for scripts
add example to change direction of arcs
fix FS#969 - File - Bitmap export: exported bitmap file locked
fix color icon cache, update script wrappers
update tree widget signals
init layer combo in WidgetFactory

povide hooks to extend layer dialog
cleanup
cleanup
update layer combo boxes
add more colors to color combo box
add slovenian translation sources
add functionality to remove listeners

completely remove layer list on demand
fix FS#970 - Unable to save file with leading / trailing spaces in layer / block names

refactor layer tools
update translations
fix return values
compile fix for windows
disable screencast tools, cosmetic updates