Merged Mario's changes

Partial fix to VAR_EXTERN vs VAR_GLOBAL check. Now considers globals declared in resources too. TODO: recursively check FB declared in the program.

Allow variables declared inside resources to be referenced by res_name.var_name

Add a new node to the abstract symtax tree, which will let us do datatype checking of FB variable declarations using the standard algorithm, and no special cases.

Print filename when debugging abstract symbol table.

Consider fb_name_decl_c a non base data type class!

Fill symbol->datatype anotation for FB declarations.

Fill in the symbol.datatype annotation in symbol classes used in derived data type declarations.

Use simple_spec_init_c inside en_param_declaration_c (will reduce need to handle it as a special case in the future).

Merged

Fixed bug in string format when translating TIME and DATETIME to STRING

Fixed bug with SFC transition datatype checking

Stripped generated files again. http://stackoverflow.com/questions/3290908/which-files-generated-by-autotools-should-i-keep-in-version-control-repository

Fixed bug in case statement with enumerated type variable as case expression

Merged

Set the symbol->datatpe of function_declaration_c

Fill in the symbol->datatype of elementary datatypes.

merge

merge

Fix divide by 0 bug.

grand merge

disable not yet complete constant propagation algorithm (currently brocken and producing incorrect results),

merge

Fix constant propagation for repeat_statement_c class.

Remove unused variable.

Implement Mario's suggestions:
- Clean up code replace merge algorithm with a function.
- Fix for_statement setting control variable to not a constant.
- Fix for_statement checking BY expression to get correct value for optimization
branch.

Thanks Mario.

Fix constant_folding missing call. [Bug found by Mario.]

Fix divide by 0 bug.

merge

Fix CPPFLAGS Makefile.am for all stage4.

Remove redundant class for get variable name.

Fix constant propagation alg. in for statement like Mario suggestion.