fix typo
doc: clean up docstring for SettingsManager
Use dictionary to index escape codes

alot/helper.parse_escapes_to_urwid()
  Changed long list of if...elif using dictionary instead.
doc: minor tweak of interface doc
Fix overwriting of theme attributes

Text mail now honor themes (don't set default attributes).
HTML color dump uses theme attributes as defaults instead of terminal
defaults.
Added focusable feature on html messages

HTML color dump body now honors theme focus attributes regardless of ANSI
escapes. The focused line will show no color other than the one set by
themes.
Fix FocusableText()

Put call of parse_escapes_to_urwid() on its right place: TextlinesList. Let
FocusableText() as it was originally.
Added option to apply background color from ANSI escapes

Added boolean option 'ansi_background' so user can choose whether background
colors from ansi escapes will be applied or not (then theme color will
remain).
doc: fix Envelope.attachments docstring
doc: clean up crypto docs
doc: move crypto docs to usage section
doc: update faq
doc: fix missing section names

in usage/commands/*
doc: clean up error message for invalid subcommands
Merge branch '0.3.4-fix-docs'
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'origin/color_html_rendering'