odds and ends (#964)

odds and ends (#964)

* odds and ends

support subseconds in exif GPSTimeStamp. While rare, some devices
provide subsecond information.

add missing include guards.

use cmake for mkicondoc, retiring the last qmake build.

provide default initializers for a couple of data members.

kill some empty statements.

* Dont' use case_ignore_strcmp for two QStrings.