The option --suppressions-list was inconsistent with other options
so renaming it to --suppressions-list.
Ticket: #1837 (--suppresions file.txt inconsistent)
Ticket #2441 (Parsing of command line arguments breaks after --errorlist)
Instead of stopping processing command line options after
--errorlist process them all. This way e.g. --verbose can be given
also after the --errorlist.
Convert include path to use internal path separators when parsing
command line. Convert back to native separators when using paths.
Ticket #2448 (Error in handling -I command line parameter)
