This includes:

- Splitting out methods of a class into stand alone functions, to make
  them easier to test.
- Adding unit tests to split out functions, testing HTML -> preview.
- Handle the fact that elements in lxml may have tail text.

Limit number of extremeties in backfill request

Refactor user_delete_access_tokens. Invalidate get_user_by_access_token to slaves.

This works around a bug where if we make a backfill request with too
many extremeties it causes the request URI to be too long.

Merge branch 'fix_integrity_retry' of https://github.com/Ralith/synapse into Ralith-fix_integrity_retry

Split out /events to synchrotron

Signed-off-by: Benjamin Saunders <ben.e.saunders@gmail.com>

Fix some bugs in the auth/ldap handler

The name 'result' is of bool type and has no len property,
resulting in a TypeError. Futhermore in the flow control
conn.response is observed and hence should be reported.

Signed-off-by: Daniel Ehlers <sargon@toppoint.de>

In case one does not define bind_dn in ldap configuration, filter
attribute is not declared. Since auth code only uses ldap_filter attribute
when according LDAP mode is selected, it is safe to only declare the
attribute in that case.

Signed-off-by: Daniel Ehlers <sargon@toppoint.de>

Only process one local membership event per room at a time

hs.get_handlers() can not be invoked from split out processes. Moving
the invocations down a level means that we can slowly split out
individual servlets.

Don't change status_msg on /sync

Include prev_content in redacted state events

Clean up TransactionQueue

Measure federation send transaction resources

Various federation /event/ improvements