Refactor build script pre/post to before/after.

[rkeithhill]

Add support for file catalog generation. Add support for updatable help generation. Also starting to work on output messages and verbose output.

[rkeithhill]

Hmm, that build failure appears bogus. If I run the same command, all the tests pass.

[rkeithhill]

I don't get this one. I cloned Plaster onto a clean machine, executed that failing command:

Invoke-psake build.psake.ps1 -taskList Test -properties @{"TestOutputFile" = $testResultsFile}

And it worked just fine.

[rkeithhill]

OK, now are getting somewhere. Seems like $profile.CurrentUserAllHosts is not defined in the appveyor environment. I'll work on this tonight.