replace mysql2 gem with pg gem
schema.rb changes for postgres
replace mysql-specific quoting syntax with db-agnostic quoting

tests are now fixed
may as well quote consistently
adapt entity values index and usage for postgres
refactor goofiness into a scope
fix value queries with more than 50 characters
typo fix
remove unnecessary association
begin using our acts_as_sane_tree fork
remove unnecessary line
remove commented out code
Fix travis build
this case is only valid for root entities
simplify a tad
bundle update acts_as_sane_tree

* this is primarily to get improved 'preloading' functionality I've added recently
* this also updated a few dependent gems.  I am not sure why.
* to disable a deprecation warning message that is now being shown, we are setting config.i18n.enforce_available_locales = true
  * this seems to be a better setting, anyway
  * we don't seem to rely on the previous behavior
  * see http://stackoverflow.com/questions/20361428/rails-i18n-validation-deprecation-warning for more info
remove redundant line
factor identical code into a method
this can't happen
use find_with_descendants