Fix layout of main toolbar

Before this commit there were two main issues:

- In small windows, the zoom controls visually floated above the page number
  (e.g. 733px).
- In small windows, the (transparent) zoom container covered the go-to-page
  input box, which prevented one from using the input field to quickly navigate
  to a different page.
[PDFHistory] Prevent the history from skipping entries in certain edge cases, when specifying an initialBookmark in the hash parameters on document load
Update webL10n to latest version + features

Base version of l10n:
- https://github.com/fabi1cazenave/webL10n/tree/b18c753c6f
4 extra commits (expected to be accepted):
- https://github.com/fabi1cazenave/webL10n/pull/38

New features compared to mozL10n:
- Support for getting translated attributes in get()

The previous version of mozL10n was based on:
- https://github.com/fabi1cazenave/webL10n/commits/0c06867a75
- diff: http://pastebin.mozilla.org/3061694

To make it easier to update webL10n in the future, I will apply
the PDF.js-specific changes in a separate commit.
webL10n: Apply PDF.js-specific changes

Based on http://pastebin.mozilla.org/3061694

1. Remove "debug helpers" and use console.log/console.warn directly (top).
2. Remove page load initialization (middle).
3. Remove window._ alias (bottom)

The original diff contained an extra entry
"Adds fallback argument to the getL10nData;",
but this was already implemented in the rebased webL10n, so it's no
longer PDF.js-specific.
Merge pull request #3691 from Snuffleupagus/PDFHistory-followup-3341

[PDFHistory] Prevent the history from skipping entries in certain edge cases, when specifying an initialBookmark in the hash parameters on document load
Improved password prompt
Increase api unit tests timeout for chrome.
Merge pull request #3527 from timvandermeij/better-password-prompt

Improved password prompt
Trying to fix #3611
Add password strings to the Swedish l10n
Merge pull request #3731 from Snuffleupagus/swedish-password-l10n

Add password strings to the Swedish l10n
Merge pull request #3730 from brendandahl/chrome-timeout

Increase api unit tests timeout for chrome.
Norwegian and Welsh locales added

Norsk (no), Cymreag (cy)
Merge pull request #3729 from prometheansacrifice/page-outofbounds

Trying to fix #3611
Read multi-byte character codes based on codespace ranges.
Properly resolves relative src for the embed tags
Prevent undefined error on null object when calling .destroy on a
document initialized with LocalPdfManager.

Per @brendandahl's recommendation, moved the terminate function out of worker
and into the PdfManager
Merge pull request #3720 from biggert/localpdfmanager-undefined

Prevent undefined error when calling .destroy on a document when LocalPdfManager is used
Merge pull request #3674 from brendandahl/cmap-squash

Read multi-byte character codes based on codespace ranges.
Merge pull request #3722 from Moistly/no-cy-locales

Norwegian and Welsh locales added