Fixes #764: Log the uid as hex

Otherwise the logs aren't processed correctly by heka.
resolved all custom git dependencies and removed mysql and heap db.

the new fxa-auth-db-mem dev dep hosts a memory db over the httpdb
api.
Merge pull request #765 from chilts/i764-hexify-uids-for-logs

Fixes #764: Log the uid as hex
too soon to rm customs-server dep
test client shouldn't send 'undefined' accept-language
Merge pull request #769 from dannycoates/lesscustom

Biggish refactor of dependencies
Merge pull request #770 from dannycoates/i759

test client shouldn't send 'undefined' accept-language
fix #700
Merge pull request #771 from dannycoates/i700-2

fix #700
added fxa-auth-db-mem to start-local. fixes #772
train-18
updated fxa-auth-db-mem should fix #773
nvm got strict again about whether "0.10" is quoted
Merge pull request #774 from jrgm/obey-nvm

nvm got strict again about whether "0.10" is quoted
updated fxa-auth-db-mem should fix #773, for real