Add support for giving list of ignored paths from CLI. This way
user can define paths one doesn't want to check (like generated
code). This first simple implementation only does exact matching,
no support for wildcards etc. And matching is always agains dir
names.
If the filtered dir name is part of the checked filename then the
file is ignored.
Ticket #1690 (Ability to exclude files and directories from checks)
* removed the 'redundant null pointer' check. sometimes it's unsafe to delete NULL pointer. and this check doesn't point out errors anyway.
* moved the 'redundant condition' check for set::remove. Moved it to CheckStl.
