This is a bugfix release.

As always, feedback welcome!

Fixes

• CLJS-1948: Possible race condition in compiler w/ parallel-build true
• CLJS-1941: cljs.compiler/cljs-files-in shouldn't return .cljc files if a .cljs file exists for the namespace
• CLJS-1940: Undeclared var warning when invoking a protocol method on a js interop form
• CLJS-1951: Missing 0 and 1 arity versions of interleave
• CLJS-1952: Bump Closure Compiler to Feb 2017 release
• CLJS-1937: Self-host: undeclared cljs.core$macros/mod when compiling cljs/core.cljs
• CLJS-1936: cljs.analyzer declares vars which are only used in Clojure
• CLJS-1949: Self-host: cljs.compiler/munge doesn't preserve JVM compiler semantics
• CLJS-1950: Eliminate instances of #^
• CLJS-1943: Self-host: cljs.pprint's macros can't be compiled
• CLJS-1945: cljs.spec/every-impl kind-fn kind-form dead code
• CLJS-1944: Can't spec generate non-vector collections
• CLJS-1946: Self-hosted: don't emit goog.require calls for foreign libs if optimizations different than :none
• CLJS-1636: Mark some symbols in core macros ns as private
• CLJS-1939: Fix Node load_file call for foreign-deps
• CLJS-1942: Self-host: cljs.env.macros and cljs.analyzer.macros can't be loaded
• CLJS-1935: When calling cljs.spec/valid?, subsequent predicates of cljs.spec/and are evaluated even when early predicate is unsatisfied