Get from server

%SCRIPT 
buildManager.runCommand("git pull ", editor.fileName())

Commit

%SCRIPT 
dialog = new UniversalInputDialog() 
dialog.setWindowTitle("Git commit / push") 
dialog.add("Commited by Olek P", "Comment", "comment") 
if (dialog.exec() != null) {
     comment = dialog.get("comment")
     buildManager.runCommand("git commit -a -m \"" + comment + "\"", editor.fileName())
}

Upload to server

%SCRIPT 
buildManager.runCommand("git push origin master", editor.fileName())

Windows users must change path to git. For example the last script should look like following:

%SCRIPT 
buildManager.runCommand("\"C:\\Program Files\\Git\\bin\\git.exe\" push origin master", editor.fileName())

UPD 21/12/2017

Show git log

%SCRIPT
buildManager.runCommand("showlog.sh", editor.fileName())

Here script showlog.sh is the following:

#!/bin/bash
FNAME='log.log' # temporary file
TEXTED='kwrite' # default text editor

git log --pretty=format:'%h : %s | Time: %cd' --graph > ${FNAME} && ${TEXTED} ${FNAME}

Compare two commits:

%SCRIPT
dialog = new UniversalInputDialog()
dialog.setWindowTitle("Choose commit:")
dialog.add("HEAD", "Recent version", "commit1")
dialog.add("HEAD^", "Elder version", "commit2")
if (dialog.exec() != null) {
commit1 = dialog.get("commit1")
commit2 = dialog.get("commit2")
buildManager.runCommand("git difftool " + commit1 + " " + commit2 + " --no-prompt ", editor.fileName())
}