first cut of github guide requested by Sara (written by Adam)
fixed typo and added pdf.
PWCSLMS-64 remove PvSetP limit
PWCSLMS-64 remove PvSetP limit & PWCSLMS-63 Implement new solar control method with discrete output steps.
updated doco for solar controller changes PWCSLMS-63 & PWCSLMS-64
updated scaling tests.
scaling bug PWCSLMS-62
Merge branch 'develop'
release 2.2.4.