Add 64bit builds to Travis
Merge pull request #51 from ethanhugg/travis1

Add 64bit builds to Travis
Improve handling of help switch in enc test app

welsenc.exe -h is now a valid command which returns success.

No longer prints help text twice in the case when the -h switch
is given along with a wrong cfg.
Merge pull request #53 from varunbpatil/cleanup

Improve handling of help switch in enc test app
Don't link to libdl when building with NO_DYNAMIC_VP defined
Merge pull request #55 from mstorsjo/no-libdl

Don't link to libdl when building with NO_DYNAMIC_VP defined