readline needs to link against ncurses or termcap

Readline built system is weird as it allows you to link against either. Since we
build termpcap and is a dependency, we link against termcap. If not the python
readline module fails to build. This could also cause some other unknown issues.
Merge remote-tracking branch 'devel/uvcdat_bug_100_fix_readline_missing_sym' into devel-master

* devel/uvcdat_bug_100_fix_readline_missing_sym:
  readline needs to link against ncurses or termcap