Add a "--notags" option for git-p4import.

P4import currently creates a git tag for every commit it imports.
When importing from a large repository too many tags can be created
for git to manage, so this provides an option to shut that feature
off if necessary.

Signed-off-by: Sean Estabrooks <seanlkml@sympatico.ca>

Documentation/git-p4import.txt

@@ -8,7 +8,7 @@ git-p4import - Import a Perforce repository into git
 
 SYNOPSIS
 --------
-`git-p4import` [-q|-v] [--authors <file>] [-t <timezone>] <//p4repo/path> <branch>
+`git-p4import` [-q|-v] [--notags] [--authors <file>] [-t <timezone>] <//p4repo/path> <branch>
 
 `git-p4import` --stitch <//p4repo/path>
 
@@ -43,6 +43,9 @@ OPTIONS
 	Specify an authors file containing a mapping of Perforce user
 	ids to full names and email addresses (see Notes below).
 
+\--notags::
+	Do not create a tag for each imported commit.
+
 \--stitch::
 	Import the contents of the given perforce branch into the
 	currently checked out git branch.