Removed some cruft from the Lexer.
Cleaned up and optimized lexer.
Moved XaviEvalute.* code into XaviTree.*
Simplified the interface to the internal parser.
Moved code for operator calls into the function call code.
Fixed some ignored syntax errors. Made the XaviTree structure completely unaware of the XaviArglist structure used by the parser. Added a syntax error type to the XaviTree structure.
Removed memory-management code that is no longer needed.
Removed useless FunctionId code and XaviStructs.h header.
Removed a needless function and moved its funcationality into another function.
Changed parser so that addition and subtraction operators are processed as functions.
Changed parser so that multiplication and division operators are processed as functions.
Changed parser so that exponent and dice operators are processed as functions.
Removed operator-handling code. Operators are now handled as functions.
Code formatting fixes.
Separated XaviNumber into internally used XaviValue and API-visible XaviResult.
Restructured the abstract syntax tree and updated relevent members and variables.
Cleaned up most of the code so that the value returned by malloc is checked. Changed XaviInternalParse to XaviParse.
Fixed a problem with the function call tester.
Moved arglist code into tree in preparation of merging Arglist functionality into Tree.
Folded arglist functionality into abstract syntax tree.