Fix objects not being testable for truthiness

The usual semantics apply, that is, variables of type 'object'
evaluate to true in a boolean context iff they're non-zero.
Make compiler invocation more Makefile-friendly
Fix functions returning objects not compiling

Previously, the call inliner would create a temporary of type object
and try to initialize it with 0. The code generator would fail as
there is no such thing as an object constant.
Add spaces around certain intrinsic function outputs

Rescript can't always differentiate between identifiers and builtins.
Fix compile error on functions calling other functions

The problem was that the function would not consider variables from
outer scopes to exist, because they were not there when the function
definition had its scopes snapshotted.
Move argument inlining into CallInliner
Add missing example file
Fix require'ing files from require'd files