Version 1.3 (June 24, 1992)
	- Much better documentation, including a tutorial.
	- The old instrumentation strategy has been replaced by a
	  better one, in effect if you use any combination of coverage that
	  excludes operator and operand coverage.  The old strategy
	  is retained for those two coverage types.
	    - The new strategy is much less of a challenge to C compilers.
	    - It uses much less stack space in the instrumented program.
	    - Instrumentation is about 20% faster.
	    - The new strategy can handle some obscure C code that the old
	      could not.
	- Various minor usability improvements.
	- Various minor bug fixes.
	- Clearer and better support for using GCC and other ANSI compilers.

Version 1.4 (January 28, 1993)
	- GCT now behaves like a true compiler.  After instrumenting,
	  it calls the C compiler.  The original source is never touched.
	  The old behavior retained as an option.
	- GCT can insert gct_readlog and gct_writelog calls for you.
	  You needn't edit the source. Original behavior retained as an option.
	- More flexible reporting tools (including per-file and
	  per-routine reports from greport and gsummary)
	- Better control over the interface to different C compilers.
	- More flexibility in editing (suppressing, ignoring) mapfile entries.
	- Previously unsupported ANSI C constructs now supported
	- Optional locking of logfiles 
	- Numerous minor usability improvements
	- Support for incremental update of mapfiles and logfiles
	  (provided by separate tools).