configure: add termination handler

To remove temporary files when script terminates due to interruption
as well as normally.  This also reduces the number of `rm -f'
commands.
configure: avoid putting \n in a message

Bash builtin echo does not translate \n while dash echo does.
configure: add version utilities
configure: refactor C++ test compilation routine
configure: refactor version and compiler type checking routines
Show required boost version
Separate required C++ compiler and dep_gen versions
Bugfix: check C++ compiler and dep_gen versions independently
Determine C++ compiler type/version without test compilation
configure: remove unused variables
Refactor C++ compiler type checking routines
Fix separator matching in config.log
Merge branch 'bugfix-configure' into development