remove unused dynamic var and related dead code
all JavaScriptFiles must provide a namespace
remove needless var stuff around cljs.env/*compiler*
the compiler environment while making the compiler infrastructure more
robust also makes it more tedious. Add a cljs.env/ensure macro that is
used by the following so an environment doesn't need to be established to
do basic things, applies to:

cljs.analyzer/macroexpand-1
cljs.analyzer/analyze
cljs.analyzer/analyze-file
cljs.compiler/emit
cljs.compiler/parse-ns
cljs.compiler/compile-file*

In the case of cljs.compiler/emit, the old emit multimethod has been
renamed to emit*
optimize ensure
make build script work on OS X & Linux
bump version in README
inline vector
inline list & hash-set
inline array-map, hash-map, tweak PersistentHashMap.fromArrays
merger