Quick overview of the call graph

Showing the recursion between the FB parser, the PP parser, and the lexer:


   				+------------------> lexGetLookAhead() --------+
   				|                                              |
   				|                                              v
   	 (begin)        (FB parsing)                (PP parsing)         (lexing)
   	fbCompile()  ->  cProgram()  ------------>  lexSkipToken()  ->  lexNextToken()
   		|               ^  |                       |     ^              |    ^
   		v               |  |                       v     |              v    |
   	   fbPreIncludes()  |  |('$include)       ppCheck()  |           ppDefineLoad()
   			  |     |  |                       |     |          (macro expansion)
   			  v     |  v                       v     |
   			 fbIncludeFile()  <--------------  ppParse()
   					(#include)    (directives)

