git plugin: add convenience aliases for git apply and git am

These are common operations when applying patches from mbox files on
mailing list based projects like U-Boot or the Linux
Kernel.

plugins/git/git.plugin.zsh

@@ -38,6 +38,7 @@ alias gapa='git add --patch'
 alias gau='git add --update'
 alias gav='git add --verbose'
 alias gap='git apply'
+alias gapt='git apply --3way'
 
 alias gb='git branch'
 alias gba='git branch -a'
@@ -257,6 +258,12 @@ alias glum='git pull upstream master'
 alias gwch='git whatchanged -p --abbrev-commit --pretty=medium'
 alias gwip='git add -A; git rm $(git ls-files --deleted) 2> /dev/null; git commit --no-verify --no-gpg-sign -m "--wip-- [skip ci]"'
 
+alias gam='git am'
+alias gamc='git am --continue'
+alias gams='git am --skip'
+alias gama='git am --abort'
+alias gamscp='git am --show-current-patch'
+
 function grename() {
   if [[ -z "$1" || -z "$2" ]]; then
     echo "Usage: $0 old_branch new_branch"