TranslationDE

Expand the qucs_de.ts with ~100 to ~200 new entries and run lupdate
with —no-obsolete. Sensfully to learn pull on github for me.
Merge pull request #128 from global667/langDE

Update translation DE
change search dialog ui
replace findText in searchdialog with signal emit
remove find again action
remove textDoc in searchdialog
add search, replace slot in textdoc, and connect
implement search replace function
remove qucsapp in search dialog
fix search fail due to disconnect
add basesearch function, update search, replace