bauhaus: make version for the visually impaired compile again
Clang-format: disable formatting for src/external/
wb_presets: Panasonic GF5

samples kindly provided by Pavel Nakonechny
wb_presets: Panasonic GH2 cosmetic corrections
collection: factor out query string for number+op subacases
collection: factor out query property listing for iso, aperture
collection: expose focal length as filter
collection: expose focus distance as filter