bumped version to 0.16.

bumped version to 0.16.

feature: added an optional len parameter for resty.md5.update(). (#33)

bumped version to 0.14.

bumped version to 0.14.

feature: added parameter check for aes.lua.

add more doc and fix buffer length error.

bumped version to 0.12.

doc: updated the copyright years.