Removing several warning in iec_std_lib.h

Code formating only.

Fix stage4 for compare expressions.

Prepare to delete search_constant_type_c -> Move the static variables from search_constant_type_c to get_datatype_info_c

Remove no longer needed search_il_operand_type_c

Also force_narrow IL instructions inside IL expressions, i.e. inside parenthesis.

Correctly generate C code for IL expressions, i.e. IL instructions inside parenthesis.

Fix bug when handling IL expressions (i.e. IL instructions inside parenthesis).

Delete debugging code, introduced by mistake in previous commit.

Fix handling of IL parenthesized expressions in generate_c_il_c

Fix processing of TIME literals (submited by Andreas)

Fix flow control analysis of IL simple instructions (i.e. IL instructions inside parenthises!)

Comment out invalid assertion.

Code cleanup: get the datatype of each entity off symbol->datatype (set in stage3 datatype checking), instead of determining it again in stage4. (NOTE: handling of IL parenthesized expressions is not working! Will be fixed later.)

Major code cleanup: IL code generation now uses symbol.datatype (filled in during stage3 data type checking) instead of determining the symbol's datatype by itself.

Do not repeat narrow algorithm for ST code, and better comments.

New visitor classes missing from previous commit.

Remove line printing debug info.

Add classes to print status of AST (use only for debugging!)

Remove all remaining NULL (undefined) datatypes from IL code.

Move is_datatype_valid/equal() to get_datatype_info_c

Fix bug related to support of SAFE datatypes.

Set datatype of il_intruction_c objects containing an ST operator.

Delete unused variables.

Use doubly linked connections for flow control graph (will be used later).

Remove deprecated search_expression_type_c

Deprecate use of search_expression_type_c (prepare for complete removal!).

Deprecate use of search_expression_type_c (prepare for complete removal!)

Deprecating use of search_expression_type_c, so it may later be deleted!

Merge

Add new get_datatype_info_c (preparing to remove search_expression_type_c)

Delete declaration of unused & undeclared functions.

Delete class elements that are not used (clean up code).

Add check whether external var matches to global var.

Also check FB passed as parameters in FB/Function calls (Thanks Andreas!)

Minor changes needed to build with pedantic flag.

Also check external/global variable consistency in configurations and FBs.

add method for printing class_name. USE ONLY FOR DEBUGING!

store POU reference to POU declaration instead of global var declarations.

Start declaration check class.

Start declaration check class.

Adjust coding style.

list_c: initial capacity. ERROR_MSG(msg,...) supports optional arguments now.

Deleting datatype checks no longer needed (with a view of making search_expression_type_c redundant).

Start adding support for data type checking of enums.

Remove comment no longer valid since introduction of constant folding.

Add some comments.

Update configure script.