ccmake: Remove incomplete support for cur_colr on old HP-UX

Enable support for the more modern Xcurses.
ccmake: Use standard getmaxyx instead of non-standard getmax[xy]

Swap out getmax[xy]() calls for single call to getmaxyx(), to support
strict X/Open conformant curses implementations, e.g. HP-UX Xcurses.
ccmake: Cleanup and simplify conditional blocks for HP-UX
Merge topic 'ccmake-hpux' into next

7a687292 ccmake: Cleanup and simplify conditional blocks for HP-UX
44f02b42 ccmake: Use standard getmaxyx instead of non-standard getmax[xy]
ee3d06a4 ccmake: Remove incomplete support for cur_colr on old HP-UX