GitLab

* Change capitalisation of CMHG file to match several #includes of the
  derived header file
* Use generic specifiers for include paths and warning suppression options
* Change to `CUSTOMRES=no` so `CModule` provides a no-op `resources` rule
  on our behalf
* Add `.gitignore`
* Enable GitLab CI
* Fix issues identified by CI, including:
  - Tabs-after-spaces
  - Buffer overflows in Auth_LMOWFv2(), LLC_AttachDriver()
  - Dead code: SMBTime(), Auth_NTv2ChallengeResponse(), Func_ReadDir(),
    Transact_getpointer(), Transact_addroutepath()