Fix EZP-23712: The content edit form moves if you put the mouse over the title

Also rewrote how the tech infos are shown/hidden to use only CSS and avoid
asynchronous tests because of a graphical effect
Removed the bottom padding on the header in the content edit page
Merge pull request #128 from ezsystems/ezp-23712_techinfo_edit

Fix EZP-23712: The content edit form moves if you put the mouse over the title