Fix places left in registration form
Fix EAgreement (don't apply protection checks)

fixes #1644
Remove travis.yml for 1.9 (tests are broken there)

NOTE: When merging into master, make sure to preserve the file in master!
Add script to "undo" account merges

- Only covers a few fields (the ones we needed to undo a certain bad merge)
- Room booking needs to be checked manually (not handled at all so far)
Fix js error in webcast/recording request

Happened when lectures used to be meetings and had contributions
Upgrade Invenio connector
Fix broken membership test operator
Fix missing POST in registrant filter
Try getting filepath with ascii encoding
Prevent error for non-existing contributions
Log failed deletion
Handle suggestions of deleted categories
Fix broken english
Updated dependency versions
Merge branch 'v1.9'

Conflicts:
	.travis.yml
	indico/ext/importer/invenio/connector.py
	requirements.txt
Add Installation guide
Improvements in install guide/highlighting
Get rid of old useless code
Merge branch 'v1.9'

Conflicts:
	doc/dev/source/index.rst
	indico/modules/rb/models/blocking_principals_test.py
Fix assistance option on reservation modification

Close #1698