pfq_property_fun added to pfq_funcional_type enumerator.
In pf_q-functional, small refactory.
Typo: NULL replaced with nullptr in C++ code.
Q_SO_GROUP_FUN_PROG setsockopt renamed Q_SO_GROUP_COMP
Major: Added support for property functions.
Minor changes...
Added predicates: less, less_eq, greater, greater_eq, equal and not_equal
get_data_size utility function added.
Removed unused is_monadic_function predicate.
Debug messages updated.
Added support to pfq_computation_compile for property functions.
Computation compile extended with high-order predicate supports.
validate_computation_descr extended for property functions and high-order predicates
pfq-lang: updated with support for high-order predicates and property functions
Added <, <=, ==, !=, >, >= predicates
Added few ip properties: ip_id, ip_tos nad ip_tot_len.
test-lang updated.