buildsystem; added REPOSITORY_VER variable in crossplatform.mk for fetching repository version.
 - using -DREPOSITORY_VERSION="$(REPOSITORY_VER)" to pass info to preprocessor.
 - we only support git for now.
 - also made version and copyright notice copy-able from the ide about box.
ide;debugger; tweaked provide source files location directory stuff for toggling breakpoints in files outside any project.
ide;debugger; fixed GdbExit doesn't wait for new valgrind threads to exit. threads were accessing deleted debugger.
ecere/gui/ScrollBar: (#1023) Fixed broken thumb dragging on large files
- int overflow on multiplication by range