Add possibility to change heating curve parameters via settings page.
IMPORTANT: new option added in config.ini. If you're updating
from previous version you need to add option hcslope = 0.7, hcpshift = 1 and hcamp = 1 in [SETTINGS] block in config.ini
1.30
hcslope = 0.7,hcpshift = 1andhcamp = 1in[SETTINGS]block inconfig.ini