Make edit toolbar accessible to screen readers

Removed redundant attributes, added aria-* attributes and properly
declared the links with role=button.
Tested with JAWS 14 and NVDA.

Bug: 24592
Change-Id: I27e18798d18b63655ea716eee2be1c7ab5303759
Localisation updates from http://translatewiki.net.

Change-Id: I5b615164ae942e8465999761f358e3e665e41de3
Merge "Make edit toolbar accessible to screen readers"
Localisation updates from http://translatewiki.net.

Change-Id: I114423c3aeeac7bded07332e1a4bba7d636b307d
Localisation updates from http://translatewiki.net.

Change-Id: I2ea214688e69bc37971db50c66fc93bb7ee5f04a
Localisation updates from http://translatewiki.net.

Change-Id: I97ea9cbaba2fde3b96a58e8ef5a275ee07bf3436
Localisation updates from http://translatewiki.net.

Change-Id: I6abc52215907e0bfb8cb21bdb7e3545f16b91aa8
Localisation updates from http://translatewiki.net.

Change-Id: I221e377e92787b41c2650dd7760de7c07b2fa9cf
Localisation updates from http://translatewiki.net.

Change-Id: I44efed4616e482a4a7c9d168456c9287689ecf98
Localisation updates from http://translatewiki.net.

Change-Id: I3f0b45b4678bd239207914471f9dcf370ca72fad
Use mediaWiki.message( ... ).plain()

Bug: 42107
Change-Id: Ic17aa1ff18528cec402bef08cace6987529f2782
Merge "Use mediaWiki.message( ... ).plain()"
Localisation updates from http://translatewiki.net.

Change-Id: I02d95202d1fa13824bf14f4dd85a685a6c252af6
Localisation updates from http://translatewiki.net.

Change-Id: I2d448499a84f626611563e5bdecd131faf8be90b
Localisation updates from http://translatewiki.net.

Change-Id: If461ab8bba5d656081dab5721d61625004016dc5
Localisation updates from http://translatewiki.net.

Change-Id: I840fc6053b6fd779b64b0b4b1164cee327cc2630
Localisation updates from http://translatewiki.net.

Change-Id: Ief3f90b0dbdd16d5b2bdea7fa448885bf4f823f3
Localisation updates from http://translatewiki.net.

Change-Id: I73f182593b2c8ca993ae1e38bfca179ffefb8f05
Localisation updates from http://translatewiki.net.

Change-Id: I7ca03214dedc13aa776ed16b7ac46737e8f9e0ba
Localisation updates from http://translatewiki.net.

Change-Id: I53b35017da07d5f582c6b61912d90a5f31602218