import mm2latexinput with cites and details

mm2latexinput.xsl has been taken as base and:

refactored
* indentation
* {"}'s and {'}'s xml-correct

major changes:
* cites are exported as \cite
* details of nodes are exported as text
* only numbered nodes are exported as \chapter, \section, \subsection, \subsubsection
* all nodes structured below are exported as nested \begin/\end{description}
* notes are exported as \todo

minor changes
* esc-sequence for {"}
* modes "trim" for @TEXT and richcontent

it works on my mindmap, further tests have to be done. please report with errors and examples to https://github.com/Docear/Desktop/issues/382
xslt 1.0 and 2.0 option with docu

I changed the root template as follows:
* XSLT 1.0 Version callable from docear as is (commented out)
* saxonb-xslt command line example

* XSLT 2.0 Version
* parameter parameter "output-base" which defaults to "content"
* creates one input file "content.tex" which \input{}s all chapter files content_1_<name_start>.tex etc.
* saxonb-xslt command line example
bugfix for #439
supressed errors caused by nodel links (#428)
always keep orphaned nodes (optionally): #419