public / sequelize

This fixes two problems in particular:
  - there was no existing way to access information about the model
    you were generating a limit and offset for, so the model has been
    added to the options
  - included where generation was done from raw SQL, making it impossible
    to support other dialects that don't support the same LIMIT syntax

add environment variable to enable logging during tests

Update inflection dependency to v1.5.2

Fix MySQL unique constraint error message parsing

Prefer index name when mapping unique constraint errors

unique constraint error

Undestroy method for paranoid models

update/clean readme

- update some of the links
- change h3 to h2 for sections
- add disclaimer about runnable not being up-to-date
- change twitter link to @SequelizeJS instead of @sdepold

When using migrations to create indexes instead of sync or when unique
index name has fields with underscores (was problem at least with
postgres implementation) then it was not possible to set custom error
message, because mapping the error thrown from database always failed.
Fixed by using indexName always for mapping the error if possible.

keep original error message when wrapping in DatabaseError

Add support for 'IS NULL' comparison

Allow removing has-many associations by id

#2338 - Associations remove[AS][plural]

Use pg-hstore for improved hstore handling

Use the new beta build env on Travis

caching is enabled
faster vms
faster boot times
(docs coming soon)

fixes #2521