Remove deprecated doc related to PHP < 5.4

magic_quotes and ze1_compatibility_mode have been removed as of PHP 5.4
Update the deprecated commands

Remove the deprecated commands and replace them by the new ones. Also
update the documentation where we were relying on the propel-gen script.
Instead rely on the propel one (which should be aliased to the propel
script stored in the propel vendor directory).
Update for some deprecated objects and methods

Update the documentation for some deprecated objects/methods:

  * containsColumn -> hasColumn
  * addParameter(array) -> setParameter(name, value)
  * Persistent -> ActiveRecordInterface
Fix a broken link to the MIT license
Fix symlink location in the installation guide
Update references to Propel 1.x generated folders

The folders generated with the propel-gen script aren't the same in
Propel 2. These folders are:

  * build/classes -> generated-classes
  * build/sql     -> generated-sql
  * build/conf    -> generated-conf

Update also the sub-structure of the generated-classes one.
Update the references to the 1.x repository

Update the documentation replacing all references to the "Propel" github
repository to match the actual one.
Move path pointing to propel to Composer's autoload

This one was easy!
Update the contribution guideline

Since the new repository's design, the process to create a pull request
has been a little bit change ; update the documentation to match the
actual one.

Also remove the contribution part in the README file and move it to the
contributing file. The README was up to date with the new testing
process.

Also update the part about fixing checkstyle. To keep clean logs and
make git blame easier, we should only fix files which have been changed.
Update svn co url since svn.github.com is out of date
Remove the Symfony 1.x documentation

Remove all the documentation related to the integration of Propel in a
Symfony 1.x project. The sfPropelORMPlugin won't be updated for the next
Propel major release (2.0).
Remove mentions about dbd2propel

The dbd2propel command has been removed. The whole cookbook on
DBDesigner is deprecated.
Update a little bit the doc for PHP 5.4
Basic update for the documentation about BaseObject
Add Windows instructions to put propel bin in PATH
Fix Propel's bin location with Composer set up
Fix a little typo on the number of generate classes
Remove references to Phing

Apart from the "Customizing build" guide which needs to be completely
updated, any reference to Phing should have been removed from the
repository.
Remove references about datasql and datadump commands

The datasql and datadump commands have been deprecated.
Remove references to the old DBDesign cookbook

Since the dbd2propel command has been removed in Propel 2.0, this guide
is useless and has been still removed in 53ab611 but there were still
links pointing to it.