Added @constructor annotation for constructors to get rid of "dangerous use of the global this object" warnings of Closure Compiler.
Restructured a conditional expressions - saves 55 bytes after Closure Compiler.
Modified envelope length to always generate an output that can be divided by 3, therefore we will not need the padding "==" for base64 strings - saves 33 bytes after Closure Compiler.
Modified build.sh to remove linebreaks - saves 7 bytes after Closure Compiler.
Modified build.sh to remove the multiple instances of base64 characterset strings - saves 191 bytes after Closure Compiler, but must make sure that "x" is not already used in jsfxr() _after_ Closure Compiler.