Fixes clobber caused by absolute paths in MK_DEPENDENCIES
Implements url_relative function
Brings support of sub-directories to BINHEADER product type
Implements hook/precommit command
Changes time precision from second to milliseconds
Implements MK_SPREADING_PARAMETERS
Removes test log if failed
Implements run_{get,set}_cmd functions
Implements 'make test/clean'
mv extensions/product_test.ext.mk -> extensions/test.ext.mk
Separates standart testing extension and products testing extension
Implements test_script() function
Makes tests extensions' variables private
Makes run comamnd extension' variables private
Implements run_script_cmd function to guess running environment from the file's extension
Defines the Python running environment
Implements test_{bin,bins} helper functions
Lets hook/precommit test completly
Lets BINLIBSTATIC's parameters' variable be ARFLAGS instead of LDFLAGS
Makes cmd_hook.ext.mk's variables as private