Split OS specific macros into make/<OS>.mk
Allow any of the commonly used 64 bit identifiers
removed unnecessary info line
Merge branch 'next' into makefile_updates

Conflicts:
	Makefile
Removed dates from comments
added OSFAMILY macro
moved ROOT_DIR macro back into explicit OS specific sections
removed unnecessary $(info) statements
moved TOOLS_DIR, BUILD_DIR and DL_DIR into main Makefile
Removed specific versions from comments to prevent bit rot, still dependent on Qt 4.8.x at this time
renamed shared.mk to system-id.mk to better represent its purpose
+sandwich
Merge pull request #639 from jan76/makefile_updates

Split OS specific macros into make/<OS>.mk