[BUGFIX] Respect language based style names on reading Word files

[sbuerk]

[BUGFIX] Respect language based style names on reading Word files

Microsoft Office saves Office document with language based style
mappings for default styles. For example, if a german based Word
version is used, it writes following to the word/styles.xml in
the container archive (*.docs):

<w:style w:type="paragraph" w:styleId="berschrift1">
  <w:name w:val="heading 1"/>
  ....
  </w:style>

versus for a english based version it would be:

<w:style w:type="paragraph" w:styleId="Heading1">
  <w:name w:val="heading 1"/>
  ...
</w:style>

The value of <w:name /> defines the internal native code
identifier, whereas the w:styleId attribute on the outer
<w:style /> tag would describe the virtual or alias name.

Later parsing of the document structure, for example the
paragraphs, references the alias (w:styleId) name of a
style. The reader code uses hardcoded RegEx matchings in
a case-insensitive manner but using the englisch speaking
variant (Header\s+d) - on the language based one, which
would not match at all.

Therefore, multiple tasks need to be done and contained
in this change:

• A alias map is implementend and used to register title
  aliases. Along with this corresponding lookup method is
  added.
• Use the lookup method to resolve for alias where the
  hardcoded language RegEx is needed to be used.
• Gathering all style alias names during reading the
  wordfile styles settings for all possible styles.

[coveralls]

coverage: 97.171% (-0.05%) from 97.217%
when pulling 13a5d65 on sbuerk:stefan-1
into 8b891bb on PHPOffice:master.