Bug 814271 - [email] Consider/try optimizing back-end start-up so databases come up fast, protocol JS load and init are deferred.  Break loads up based on account types.  r=asuth

Land https://github.com/mozilla-b2g/gaia-email-libs-and-more/pull/128
Merge pull request #8256 from asutherland/email-land-deferred-load

Bug 814271 - [email] Consider/try optimizing back-end start-up so databa.ses come up fast, protocol JS load and init are deferred.  Break loads up based on account types. r=asuth