Add .gitignore and .gitreview files

Add the .gitignore and .gitreview files to the asterisk repo.

NB:  You can add local ignores to the .git/info/exclude file
without having to do a commit.

Common ignore patterns are in the top-level .gitignore file.
Subdirectory-specific ignore patterns are in their own .gitignore
files.

Change-Id: I4c8af3b8e3739957db545f7368ac53f38e99f696
Tested-by: George Joseph

utils/.gitignore

@@ -0,0 +1,24 @@
+aelbison.c
+aelparse
+aelparse.c
+ast_expr2.c
+ast_expr2f.c
+astman
+astcanary
+astdb2bdb
+astdb2sqlite3
+check_expr
+check_expr2
+conf2ael
+db1-ast/libdb1.a
+hashtab.c
+lock.c
+md5.c
+muted
+pbx_ael.c
+pval.c
+smsq
+stereorize
+strcompat.c
+streamplayer
+threadstorage.c