Fix re2 build error on OS X

Review 1209 by @Tryneus
Fetch nothing by default and bump dep versions
Bump to browserify 3.0.0 and remove get/set with []
Merge branch 'nofetch' into next

Review 1201 by @neunino and @Tryneus
Closes #1231
Closes #1803
Document the build system

Review 1207 by @mglukhovsky
Closes #1946
Merge branch 'next' into sam_alt