#474 provide a runtime configuration to hide the cursor for extended screenio

[Simon Sobisch]

The implementation is very similar to COB_INSERT_MODE but would be a boolean type yes/no and also uses curs_set to hide the cursor, if toggled back then it would show the cursor depending on the current insert mode.

I'm not sure on the name yet, you are free to come up with something, maybe COB_HIDE_CURSOR?
In any case, steps to do:

• inclusion in runtime.cfg -> docs first
• inclusion in common.c (config table) and common.h (setting structure)
• inclusion in common.c to forward to screenio.c
• screenio.c -> actual handling
• testcase in testsuite.src/run_manual_screen.at (the possibly hardest part)
• note about that in the NEWS file

[Ammar Almorsi]

Included with [r5314]