* stable-3.1:
Respect container.replica option in gerrit.sh script
Add guidelines on choosing a branch for contributions
Restore keyboard shortcut for expand all diff context
In plugin list, add placeholders for missing versions
Add Api version to plugin list in PolyGerrit UI
Add Api version to `plugin ls` Ssh command text format
Expose Api version through PluginInfo
When writing temporary plugin files, ensure the directory exists
Update git submodules
Update git submodules
Manually bringing the changes from gr-plugin-list.html to
gr-plugin-list_html.js to make up for the ES6 module conversion
in dbe95453.
Change-Id: I1194af63348a9ac29fda641539d978a0b8aacfe1
b296c465cd