mod: rebuild distribution
fix: exclude file reading time in benchmark
mod: remove wrapper around number
rm: wrapper around real and boolean
add: test cases for environment
add: implement environment lookup
add: test for look up in parent environment
add: implement environment define
add: integrate environment
Merge branch 'faster-number' into optimize-variable-lookup

Conflicts:
	src/toplevel.js
mod: rebuild parser
fix: unit test for parser
Merge branch 'faster-number' into optimize-variable-lookup
rm: bool class
Merge branch 'faster-number' into optimize-variable-lookup
Merge branch 'master' of https://github.com/qiao/r7rs.js