CI: fetch also master branch to build doc

See merge request mhm/mhm!71

Back to work 5.11.2-dev0

See merge request mhm/mhm!70

smhorizon_bugfix

See merge request mhm/mhm!67

Update INSTALL.md

See merge request mhm/mhm!68

Small text updates based on merge request 63: !63 (closed)

This is a bug fix. In the old version we mistakenly correct tmp_rootfraccoef directly if it is not between 0 and 1, but we should actually make sure that FCnorm is always between 0 and 1. This will in turn also secure that tmp_rootfraccoef is between 0 and 1.
Case 10 and 12 files are also updated accordingly. All test cases in CYGWIN-Python are successful.

Release 5.11 back merge

See merge request mhm/mhm!61

[Fix] Units and Constants cleanup

Closes #102 and #101

See merge request mhm/mhm!59

mo_common_constants: unused 'DaySecs' already present in 'mo_constants' as 'DaySecs'; use this in mo_pet