* Improved Boost header check and messages. Don't let silly buggers
specify --without-boost.
* Don't check for libintl.h, as bison-generated parser doesn't use it
unless YYENABLE_NLS and ENABLE_NLS are defined, which they're not.
Conditional seems clearler without AS_IF, since we don't have multiple
tests.
Completed proper configure test for Scope.
Converted echos to AC_MSG_WARNs for test warning.
Merge branch 'master' into unique_ptr_test