made loading the helpers smarter:

[kellyredding]

• only requires a helper if it exists (safe_require)
• more robust user options path expansion
• won't swallow load errors generated by bad requires in helper files
• closes #82

@jcredding - check this out for me, see if it accomplishes what you want.

[kellyredding]

@jcredding - also any word on this one?

[jcredding]

@kelredd - looks good, ship it