Updates self:: References to static::

Replaces several `self::` references with late static binding `static::` references, which gives a more predictable reference behaviour.
Fix PHP code block
Always use a "phinx_" prefix with in tests
Add spatial types to AdapterInterface: geometry, point, linestring, and polygon
add support for spatial types to getSqlType
add geospatial column names to getColumnTypes
add test for geo types in mysql
Merge pull request #264 from nixxquality/patch-1

Fix PHP code block in documentation
Merge pull request #182 from jbourdin/0.3.x-dev

#170 : Try to locate phinx.php
fixing merge conflicts
Merge branch 'cyrusboadway-feature/static-over-self' into 0.3.x-dev
Merge branch 'ushahidi-fix-wildcard-permissions' into 0.3.x-dev
adding phinx url
improve command help
add a demo gif
Merge branch '0.3.x-dev' of github.com:robmorgan/phinx into 0.3.x-dev
update terminal gif
rename readme. following other php projects
updating to release 0.3.7
Use a faster case-insensitive string comparison