Paragraphs formatting improvements

No margins between .paragraph classes plus text indentation between two adjacent .paragraph classes.
Fix for incorrect .ttf MIME type
Transition from square bracket to superscripted footnotes
CSS style footnotes clean up
[Mobi] CSS improvements for paragraph and footnotes
[ePub] Fix for inconsistent styles between on-line reader and ePub.
[Mobi] Fix for inconsistent styles between on-line reader and Mobi.
[ePub Mobi] Removed unnecessary annotations clutter. Make them according typography rules
[ePub, Mobi] Smaller text-indent in paragraphs.
Use CSS styles also in HTML TOC
[Mobi] Mobi output improvements

1. Produce dual Mobi file by default (Mobi7 + KF8). Much nicer and
richer experience on Kindle devices.
2. Embed fonts in Mobi.
3. Remove obsolete Mobi stylesheet (mobi.py uses epub css by default)
4. Add flag with-full-fonts to epub.py as it is required for mobi.py to
produce working subset of fonts by calibre.
5. Ignore margins option by default to ensure that result mobi file
will use Kindle devices own margins.
Fix for Epubcheck Version 3.0.1 validation warning

WARNING: OEBPS/toc.ncx: meta@dtb:uid content 'sample' should conform to
unique-identifier in content.opf:
'http://wolnelektury.pl/katalog/lektura/sample'
Fix for missing xml declaration of content.opf and toc.ncx

Lack of xml declaration causes failed ePub validation with Epubcheck
Version 3.0.1
Fix for dc:creator and dc:date tag – make it as described in OPF 2.0.1 spec.

According to an example from OPF 2.0.1 spec:
<dc:creator opf:file-as="King, Martin Luther Jr." opf:role="aut">
        Rev. Dr. Martin Luther King Jr.
</dc:creator>

Regarding to dc:date change: Sigil throws  with xsi:type in dc:date.
[ePub] Added conversion from 3-letter to 2-letter (if available) language code

The change-set is intended to fix various ebook readers problems
regarding not recognized 3-letter (bibliographic) language code.
[ePub] Fix for error validation with epubcheck 3.0.1 in multi-volume books

ERROR: example.epub/OPS/toc.ncx(24,47): assertion failed: different
playOrder values for navPoint/navTarget/pageTarget that refer to same
target
[epub, mobi] CSS improvements - better interoperability on various readers
[epub, mobi] Fix for a problem with epubs, mobi in drama ebooks without acts
Revert "[epub, mobi] Fix for a problem with epubs, mobi in drama ebooks without acts"

This reverts commit 0081ccb8e51026b5af824b3c641648d23155f1e1.
Revert "Revert "[epub, mobi] Fix for a problem with epubs, mobi in drama ebooks without acts""

This reverts commit afc2b870c1646c8d6c1b754d4ee44aa059e834c9.