Use selected_int_kind(13) to get an 8-byte integer

Needed for tests to compile with NAG compiler. See Issue #5.
Test for NAG compiler and add the -mismatch flag

Test for NAG compiler in configure.in and add the -mismatch flag to FCFLAGS
 Needed for compiling ftest.

Also regenerate configure using autoconf 2.69
Define MYF90FLAGS and remove ctest2 and ftest2

Define the MYF90FLAGS Macro which was referenced on the compile line
but not defined.  Use same as mpi-serial/Makefile defiition.
This is needed to pass in flags determined by configure.

Don't build ctest2 and ftest2 by default when doing "make tests".