Update README.md
Add replace icon.
Also in CalamaresUtilsGui
New ReplacePage
Compile ReplacePage
Hook up ReplacePage in ChoicePage and PartitionViewStep.
GB -> GiB
Don't rely on the activated signal in ReplacePage.
Improve messages in Replace page.
Fixes CAL-155
Store osprober output in GlobalStorage.
Use osProber output in ReplacePage.
CAL-155 #close
Fix issue with partition selection preview not being updated.
Merge master