[ENH] add event date when deleting events from a category

*closes #1353
[REF] Created modules.scss and moved categ
[REF] Moved html to template for conf deletion
[MIN] Added missing license text in scss
[FIX] missing fields in edit user form

*closes #1346
[FIX] ContributionParticipation not updating phone
[FIX] Chairmen missing after creation

* Edited users did not appear after creation
* As well, phone number not taked after adding user
* closes #1334
[MIN] Added python-ldap to requirements
[ADD] Added PendingConfManager
[MIN] Minor changes and naming
[FIX] Removed ldap requirement

Made it optional, people should install it only if they need it.