Limiting the size of issuable description and comments to 1_000_000,
which is close to ~1MB of ASCII characters, which represents 99.9% of
all descriptions and comments we have in DB at the moment. This should
help prevent DoS attacks when comments contain refference strings.

Also this change updates regexp matching the namespaces paths by
limiting the namespaces paths to Namespace::NUMBER_OF_ANCESTORS_ALLOWED,
as we allow 20 levels deep groups.

see https://gitlab.com/gitlab-org/gitlab-ce/issues/61974#note_191274234

https://gitlab.com/gitlab-org/gitlab-ce/issues/19186

Also release `u` from TOP_LEVEL_ROUTES
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

It takes a lot of lines to move a script

More aligned design. More functionality.

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

This integration no longer works and does not appear to be supported.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/39697

the ci status icons are generated client side, wo we don't need the
static files anymore.

for `emails` to be a top level route

These don't seem to be used anywhere, so can be removed.