libXmu 1.2.0

• configure: raise minimum autoconf requirement to 2.70
• src/Makefile.am: Remove hardcoded -D_BSD_SOURCE
• configure: Use LT_INIT from libtool 2 instead of deprecated AC_PROG_LIBTOOL
• test: Convert test code to use glib test helpers
• test: Add simple test cases for functions in src/RdBitF.c
• test: Add simple test cases for functions in src/CursorName.c
• test: Add simple test cases for functions in src/Lower.c
• test: Add simple test cases for functions in src/StrToBS.c
• test: Add simple test cases for functions in src/StrToGrav.c
• test: Add simple test cases for functions in src/StrToJust.c
• test: Add simple test cases for functions in src/StrToLong.c
• test: Add simple test cases for functions in src/StrToOrnt.c
• test: Add simple test cases for functions in src/StrToShap.c
• test: Add simple test cases for functions in src/reallocarray.c
• XmuReadBitmapDataFromFile: set close-on-exec when opening files
• unifdef hpux
• unifdef Lynx
• Remove #ifndef notdef checks
• unifdef SYSV
• Use XtAsprintf to simplify os_name string generation
• libXmu 1.2.0