Update usage and readme for zipalign.
Added the "-c" flag to the README, and added a short description of the
flag meanings to the usage output. Threw in an AOSP copyright one-liner
for good measure.
diff --git a/tools/zipalign/README.txt b/tools/zipalign/README.txt
index a2e1a5e..9c7d07e 100644
--- a/tools/zipalign/README.txt
+++ b/tools/zipalign/README.txt
@@ -1,7 +1,9 @@
zipalign -- zip archive alignment tool
usage: zipalign [-f] [-v] <align> infile.zip outfile.zip
+ zipalign -c [-v] <align> infile.zip
+ -c : check alignment only (does not modify file)
-f : overwrite existing outfile.zip
-v : verbose output
<align> is in bytes, e.g. "4" provides 32-bit alignment
@@ -29,3 +31,5 @@
By default, zipalign will not overwrite an existing output file. With the
"-f" flag, an existing file will be overwritten.
+You can use the "-c" flag to test whether a zip archive is properly aligned.
+