complexity-1.13-bp160.1.12

- update to 1.13:
  * fix ignore pattern option (-I)
  * updates to tests and build tooling
- drop obsolete texinfo macros
- remove keyring and signature as they don't validate

- Override man page date (boo#1047218)

- Small modernisation of spec file

- Use noun phrase in summary. Reduce description hype.

- Add gpg signature
- Run tests during build

- Require pkgconfig(autoopts) for building

- GNU complexity 1.10