removed 'runtest/' targets; simplified make
updating make/manual to use STANAPI_HOME variable
removed call to detect_make
setting CC_MAJOR and CC_MINOR directly so it doesn't get called multiple times.
set OS variable directly
removed spurious line from make/manual
adding a comment for the manual
removed make/models; it is unused now
removed target mangling from os_win
cleaned up make/tests
added comments to test