- Improve icheck rules in Makefile.am


include/Makefile.am:
  Remove m_ctype from BUILT_SOURCES, it has been in bk for a looong time.
  Improve the icheck rules
   - Abort make if icheck fails to compare, very important.
   - Don't include include files from /usr into the icheck file. Avoids problem when running
     icheck on different machines.
   - If no icheck is availabel, touch the mysql_h.ic file so it exists for "make dist"
include/mysql_h_abi.ic:
  Remove all include files from /usr, no need to check that!