MOBI Out: Fix regression causing missing v-margins

MOBI Output: Fix regression in 0.9.31 that caused vertical margins
specified on some block level elements to be ignored. Fixes #1186533 [Regression: some margins lost when converting to MOBI](https://bugs.launchpad.net/calibre/+bug/1186533)
Converted libiMobileDevice errors to negative numbers to match error reporting.
Remove escapemagazine.pl store
Merge pull request #5 from GRiker/master

Reformatted libiMobileDevice error codes to match reporting values (negative numbers).
Fix string.
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DOCX: Nested tables and block/run table styles
DOCX tables: override processing
Filter device list for repeating entries (occurs under Windows occasionally).
Merge pull request #6 from GRiker/master

Filter device list for repeating entries (occurs under Windows occasionally).
Update Metro News NL

Fixes #1186861 [Update of Metronews-NL](https://bugs.launchpad.net/calibre/+bug/1186861)
DOCX: Floating and justified tables
DOCX Tables: Row styling
HTML Input: Avoid spurious log warnings

HTML Input: Avoid spurious log warnings about unspecified
language/creator when these are actually specified on the command line.
Fixes #1186899 [Apparently-spurious "Language not specified" errors from caliber-convert](https://bugs.launchpad.net/calibre/+bug/1186899)
E-book viewer: Keyboard shortcuts for Back/Forward

Fixes #1186928 [Missing keyboard shortcut in the viewer](https://bugs.launchpad.net/calibre/+bug/1186928)
pep8
DOCX tables: Cell styling
Fix sub table double rendering
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Fit the viewer preferences on 600px screens

Fixes #1186927 [Configuration dialogs too wide on small screens](https://bugs.launchpad.net/calibre/+bug/1186927)