Workaround for broken linux installs with encoding set to ANSI_X3.4-1968

Got a second bug report from a user running such a system today. So
workaround it.
Refactor HTML syntax highlighter too keep track of tag nesting

This is needed for the eventual implementation of inline spellcheck
Start work on managing dictionaries in calibre
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Add ISO 3166 country codes
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Implement loading of both builtin and user installed dictionaries
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Start work on dialog to manage user installed dictionaries
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Start work on adding dictionaries
Add/remove for dictionaries from OpenOffice extensions  works
Implement renaming of dictionaries
Integrate the dictionary widget into the editor preferences
Keep track of the current book's locale as a separate global variable for performance
Refresh all editors after changing dictionaries
Add Spanish and English (GB) builtin dictionaries
Add code to get all words from a ebook with their declared locale
Try to use the right country variant english dictionary by default, based on the users locale settings
Ignore title/alt attributes on some tags