Changes

Change doc strings to start with uppercase letter
Except Units.mo

Change "... value" => "Value in ..."
Applying sed -i 's/\(.*\)\"\(.*\) value\"\(.*\)/\1\"Value in \2\"\3/g' Units.mo 

Change text in docstring from upper to lower case

Unified doc strings of conversion functions
The only exceptions are "Celsius", "Kelvin" and "Rankine" for which I kept the uppercase spelling

Change "Kelvin" to "kelvin" 
according to http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=112-02-08

Change "Celsius" to "degree Celsius"
see http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=113-04-17

Change "Fahrenheit" to "degree Fahrenheit"
according to https://dictionary.cambridge.org/dictionary/english/fahrenheit
as this term is not listed in electropedia

Chang "Rankine" to "degree Rankine"
according to https://www.convertunits.com/from/kelvin/to/degree+Rankine
as this term was not found on electropedia

Change "electrical current" to "electric current" 
according to http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=121-11-13

Change "electrical potential" to "electric potential"
according to http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=121-11-25

Changed "electrical voltage" to "electric voltage"
not listed in electropedia

Change "electrical impedance" to "impedance"
according to http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=131-12-43

Change "electrical admittance" to "admittance"
according to http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=131-12-51

Change "complex electrical power" to "complex apparent power" according to http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=131-11-39

Change more doc strings to start with uppercase letter

Change Joule to joule

Change Watt => watt and Joule => joule