Allow for parameters in instrument definition file

[Anders-Markvardsen]

Allow, for example, the ‘x’,‘y’ or ‘z’ position of a
component defined in an instrument definition file (IDF) to be
determined by values in the logfiles of ISIS measurements.

The user should be done allowing to specify `` elements
in the IDP that have the attributes:

parameter-name (e.g. ‘x’) type (default = double) logfile-id (equal to logfile filename minus run number and file extension) eq (short for equation: value from logfile may need to be converted) extract-single-value-as (how to extract value from logfile)

[Anders-Markvardsen]

This issue was originally trac ticket 362