Cleanups in hooke.driver.picoforce

Cleanups in hooke.driver.picoforce

Scaling adjustment:
* Use 'z piezo gain' in bit->m conversion (is this correct?)

Info field renames for clarity and consistency:
* 'z piezo magnification' -> 'z piezo gain' (is this correct?)
* 'z piezo scale (V/bit)' -> 'z piezo sensitivity (V/bit)'
* 'z piezo scale (V)' -> 'z piezo range (V)'
* 'raw-data' -> 'raw data'

Also:
* Stripped trailing whitespace.
* Comment typo correction 'inzrease' -> 'increase'