Add manual pages for vmnetx and vmnetx-generate

Closes #28.
Add license boilerplate to manual pages
Add VM lifecycle description to vmnetx-generate.1
Clean up options in vmnetx-generate man page
Fix indentation of manual pages
Add modes to vmnetx-generate man page, fix indent
Add examples and clean up vmnetx man page
Generate man page versions at build time
Clarify difference between nxpk and netx files
Clarify options/modes in vmnetx-generate manpage
Line-wrapping fixes
Man page cleanups
Merge branch 'manpages'