Move translation subdirectory

I move translation files into subdirectory named translations so they will not messed up with source files.
I test autotools and Cmake by myself, and there is no problem with them. But everyone can tried them and check they will work.
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another issue I fixed in commit a54d987 is that
I usually install qucs on the path prefix homedir/bin
in the Linux implementation, it remove all /bin so my prefix will be homedir only, this cause my qucs cannot load language files correctly. I change to parent directory of prefix/binarydir so it can find setting correctly.