chore(engine): Added load.php to load engine code without booting

This is useful during testing and installation
feature(aalborg_theme): adds support for .elgg-button-special and button sizes

Fixes #2954
fix(css): strings together elgg-button and button sizes
Merge pull request #7142 from PerJensen/elgg_button_special

feature(aalborg_theme): adds support for .elgg-button-special and button...
Merge pull request #7119 from ewinslow/load-engine-without-booting

chore(engine): Added load.php to load engine code without booting