Add empty SaveListener.
Implements SaveListener.
Rename SaveListener to APNGAsmListener.
Create CustomAPNGAsmListener for cli.
Add APNGAsmListener::onPreAddFrame() and APNGAsmListener::onPostAddFrame().
Create shell script for disassemble test.
Merge pull request #14 from apngasm/apngasmlistener

Apngasmlistener