add alias of `modulo`, `remainder`, `quotient`
`quotient` is defined in base
implements delete-duplicates(!) tail-recursively
Merge pull request #152 from stibear/srfi1

implements delete-duplicates(!) tail-recursively
update gitignore
use isdigit
add isdelim
[bugfix] EOF is a delimiter
syntax error around comma
fix negative number reader
block comment reader must not consume the character right after the
comment end
[bugfix] compound literals should consider inner comments
[bugfix] make-promise makes a promise that is done all along
support infinity and nan literals
Merge pull request #131 from KeenS/missing-functions

( ref #130 ) Missing functions
update xrope
fix xr_put
make no-act: direct error logs to /dev/null
don't run make test in debug mode on travis