Test for libcurses/libncurses in addition to termcap
Add explicit cast to char pointer to avoid gcc 4.8 warning

This avoids warnings like when building on gcc 4.8:

cursor.cc: In constructor ‘CCursor::CCursor()’:
cursor.cc:59:27: warning: deprecated conversion from string constant to ‘char*’ [-Wwrite-strings]
    no_lines = tgetnum("li");
                           ^
Increase bash test path length

On Archlinux /bin/sh is a link to "../usr/bin/bash" and will not fit in the 10
byte string