merging with Laurent's patch.

Print correct error message when handling IL function calls.

Edit error message.

Add EXPT widen table.

Some stupid code cleanups.

Some code cleanups.

Clean up the code.

Fix error messages of il function calls - it now prints out location info of first parameter.

Clean code for printing errors in expressions.

Clean code for comparison operations & operators.

Cleaning up XORN, ANDN, and ORN operator code.

Cleaning up some code.

Add 'widen' tables for AND, OR and XOR operations.

Add MOD widening table, and some code clean-ups.

Re-organizing the code.

Change setting of deprecated_operation from fill to narrow_candidate_datatypes_c.
Expand widening tables for ADD, SUB, MUL and DIV.

Clarify some details in the comments.

Add check widening status for IL operator.
Fix check widening status for ST expression.

Fix remaining 'widen' tables.

Fix some 'widen' table entries.

Add a TODO comment.

Clean up code, and add support for 'safe' version of literals.

Bringing comment up to date.

Semantic verification of NOT operator.

Fix bug in building structured variables.

Delete unecessary copy_candidate_datatype_list() function.

Delete no longer needed copy_candidate_datatype_list() function.

Narrow IL lists twice, in order to handle JMP to labels before the JMP itself.

Do not allow duplicate values in candidate datatype list.

Handle JMP to labels preceding the JMP instruction itself.

Correctly handle JMP and RET IL operators in flow control analysis.

Fix filling candidate datatypes of JMP operations

Remove spurious printf()s, used during debugging session.

Add missing files.

Continue adding support for semantic verification of JMP and RET.

iAdd warning for deprecated operations.

Change prev_il_instruction to a vector<>

Some small cleanups.

Add support for semantic verification of CALC, CALCN, etc..

Finish support for semantic verification of IL paranthesised expressions.

More changes for support of semantic verification of il_expressions

Start of support for IL expressions (parenthesis).

Cleaning up the code.

Fix a few more bugs related to FB/function calls in IL.

Semantic verification: Add compatibility check for parameter direction in function invocation.

Add support for semantic verification for implict FB calls in IL (e.g. PV ton_var)

Start of support for semantic verification of FB calls in IL using special IL instructions.

Delete some comments.

Change name help function.

Update comments on general architecture.

Narrow IL code backwords, so as to correctly handle invocations to overloaded functions from IL code.

Code cleanup.

Add printing of semantic errors when calling FB from IL.

Fix typo error in some il visit in fill_candidate_datatypes_c class.

Add semantic verification of FB calls in IL (not yet complete - missing printing of errors!)

Add support for semantic verification of function calls in IL.

Add TODO comment, and delete unused debugging code.

Delete un-used code.

Change negation expression (neg_expression_c) to only allow signed data types.

Move elementary_c::to_string() to datatype_functions.cc/hh