[+] Better build script

tools/build_bash.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+# This script is used to build a customized Git Bash for windows pacakge that only include bash and no other unnecessary files
+
+# Get script directory
+DIR="$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
+cd $DIR/../dist
+
+# Get the git distribution if it doesn't exist
+if [ ! -f git.tar.bz2 ]; then
+  # NOTE: Git for Windows v2.44 is the last release to support Windows 7 and 8
+  URL="https://github.com/git-for-windows/git/releases/download/v2.44.0.windows.1/Git-2.44.0-32-bit.tar.bz2"
+  wget $URL -O git.tar.bz2
+fi
+
+# Unzip the git distribution to git directory
+# Ignore the unnecessary files
+rm -rf git
+mkdir git
+tar -xvf git.tar.bz2 -C git --exclude-from="$DIR/bash_ignore.txt"