HDI temperature monitoring

Added HDI temperature monitoring.
Removed debug objects from GUI. Added safety check in api.cc.
Merge branch 'master' of https://github.com/psi44/pxar
added a function returning HdiType
Temperature monitoring is shown only if HdiType==fpix.
Clean up code : remove debug messages, and set appropriate indent.
Merge branch 'master' of https://github.com/hsatoshi/pxar
adapt PR to local coding style
slight rearrangement of display (and truncation of significant digits)