MySQL connection dsn, charset support

 - added charset support for MySQL dsn string
 - added charset parameter to the phinx configuration
 - updated configuration documentation
Update documentation. (Some little documentation for #146)
Documentation for configuration file features added in #60.
Merge pull request #150 from tag/dev-docs

Update documentation to include SQLite
Merge pull request #151 from tag/dev-docs-config

Documentation for configuration file features added in #60.
copyright 2014
merge in 0.2.x-dev
updating to 0.3.0
use `empty` to check $options['port']

i want use the `port: %%PHINX_DBPORT%%`, but other people maybe like the default port,
so just given a empty port config.
Added valid column types list

I always have to go routing through the source code to find this, so thought it would be useful to include in the main documentation.
Minor whitespace cleanup
Merge pull request #190 from coatesap/0.3.x-dev

Added valid column types section
install improvements
fix copyright
Adds tests for JSON format config files.
Adds support for JSON config files.
Corrects exception message typo.
fixes PR #171.
Fixes #134. Merge branch 'charset' of https://github.com/szachara/phinx into szachara-charset
fixes PR #193. remove trailing spaces.