Style update

changed the css to add the same 10px margin at the bottom of each
section
Link to collection of pattern implementations

See https://github.com/domnikl/DesignPatternsPHP
Tweak example code for PSR-1/PSR-2 coding standard
Update 07-01-01-Databases.md
Removed reference to maven

The php-maven.org project has not been maintained for the last couple of years.  It looked promising but doesn't work out of the box, and searching the web, I couldn't find anyone successfully getting it working recently.  It looks like a lost cause for php.
Use site.baseurl in stylesheet URLs
fixed inconsistent naming of example function
Merge pull request #427 from florianletsch/gh-pages

Fixed inconsistent naming of example function
Merge pull request #418 from olso/patch-1

Added links pointing to PDO docs
Merge pull request #421 from pjwiseman/patch-1

Removed reference to maven
Merge pull request #417 from dave1010/patch-1

Tweak example code for PSR-1/PSR-2 coding standard
Merge pull request #384 from Mihailoff/patch-1

Link to collection of pattern implementations
Merge pull request #349 from ericmartel/style

Style update
Merge pull request #422 from mjnaderi/gh-pages

Use site.baseurl in stylesheet URLs
Merge remote-tracking branch 'upstream/gh-pages' into gh-pages