The modules file had a few errors that prevented slang from being built.
First the src/elfobjs file needed to be created before make started.
Second it needed to be configured without external png, pcre and onig
libraries it doesn't need for this application.
The whiptail binary will allow us to create GUI menus from bash scripts.
It is included in the newt library, which depends on slang. To enable,
the board configuration file should add CONFIG_SLANG=y and CONFIG_NEWT=y
