Update snap package to grade stable

Add snap package build file

Minor indent fix

Also check for maximum character width in checkfont

Disable TLF fonts to build with mingw32 in travis

Prevent string overflow in chkfont suffix check

Fix return type for getc() call in chkfont

Comment out unreachable code

Also set the linker command for travis-ci

Fix clang-sanitizer compiler settings for travis-ci

Use correct compiler in travis-ci

Add travis-ci control file

Also fix make vercheck message line breaks in MacOS X

Fix make check message line break in MacOS X

Also test for MacOS X to include Unix headers