Merge pull request #252 from ivanlanin/rtf

Passed Travis. Merged.
Added Line element
Fixed some Travis build errors
Second attempt to resolve Travis build errors
Final try to resolve Travis build errors
Some adjustments for the new `Line` element #253
#193: Heading numbering
Merge branch '#193' into develop
Bugfix for #236 (OpenOffice crash when opening DOCX) and paragraph style refactoring
QA: Docblock improvements and -q parameter for phpdoc
Decompose Shared\Html
#80: Basic HTML reader
Documentation updates and test fix for #254
Add $nestedLevel to elements
#245: Basic table support in RTF writer