[bukuserver] functional tests

[LeXofLeviafan]

automates a part of these tests (by examining response HTML):

• the bookmarklet popup form
• bookmark editing forms
• configurable functionality

also:

• changing the views to access runtime values of BUKUSERVER_PER_PAGE & BUKUSERVER_URL_RENDER_MODE instead of memorising initial ones
• simplifying last_page() logic

[jarun]

@rachmadaniHaryono please review.

[LeXofLeviafan]

Note: did a rebase

[LeXofLeviafan]

…Come to think of it, the locale support doesn't work without installing flask-babelex; so we should either mention it in the readme, or add it to the server deps.

I think I prefer the latter as it appears that flask-admin is going to change the dependency to flask-babel on the next release (which isn't a drop-in update for us as it initialises locale-selector differently). Though it seems like flask-babelex will still be supported, it's still a deprecated package.

[jarun]

@LeXofLeviafan @rachmadaniHaryono can this be merged?

[LeXofLeviafan]

Yes, as far as I'm concerned. Still waiting for feedback from the other guy tho.
(I've also got no responses on the locale support thing from my last comment…)

[jarun]

Thank you!