Added new and updated translations, added transifex config, changed readme

+ Catalan translation files
+ German translation files
+ Dutch translation files
+ Thai translation files
+ Spain translation files
# added language to related xml-files
# french translation files from transifex (minor binary changes, for autocheck if something has changed)
+ .tx transifex config to use with transifex client (instructions on how to use tx-client in wiki)
# rename readme file to use markdown code
+ .gitignore to prevent unwanted commits (such as the tx.exe or mac/win crap)

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.gitignore and tx-config have to be updated again if further languages are added, etc...