Make Writer.t concrete in Future_std
Merge pull request #4 from pveber/patch-1

Make Writer.t concrete in Future_std. Should have been done in cb7001994f419cabc85782e9a0e607c0d0dcc358.
async: equate Writer.t type

Should have been done in cb7001994f419cabc85782e9a0e607c0d0dcc358.
Update wrt core 111.17.00
update Travis scripts

Don’t specify Core version, i.e. test against latest version in main
opam-repository. Other minor improvements.
Merge pull request #5 from pveber/core_111_17_00_update

Update wrt core 111.17.00
Reader, Writer: add some file operations
Future_std: replace Stream with Sequence

Core has Sequence since 111.13.00, which is a Stream-like data
structure. Thus we can use this now and remove dependency on cfstream.

Remove `Pipe.read` from signature because wasn’t immediately obvious
how to provide this for Sequence, and we weren’t using it in Biocaml.
use opam's %{jobs}% variable

Related to #6.
opam, travis: remove cfstream dependency

Should have been done with ee50b2ff2998fe4c78ebd3316993fe91bec76d8c.
opam: require core >= 111.17.00

Should have been done with aa7027444d7d9c10635c4c70b6b1b0646a65165c.
OMakeroot: lwt & async lib install now optional

Although we had compilation of future.lwt and future.async optional,
the install target assumed they existed. It would then fail if the
corresponding files didn’t exist. Now using ocamlfind’s -optional
argument to handle correctly.
Future_std: replace Sequence with Stream

Effectively undoing ee50b2ff2998fe4c78ebd3316993fe91bec76d8c.
Pipe: add read, junk, and read_and_leave

`read` was removed in ee50b2ff2998fe4c78ebd3316993fe91bec76d8c, and is
now added back.
travis, opam: add cfstream dependency

Should have been done in fb0df65f57d1de7afa51edea1a3052aadee26c37.
add Deferred.List
define Deferred.unit
OMakeroot: fix install bug

OMake doesn’t create symlinks to all source files if they aren’t
needed. For example, future_async.mli doesn’t exist under _build if
COMPILE_LIB_ASYNC=false. This would cause `omake install` to error out.
Could put mli files under -conditional option, but this works too.
Closes #7.
simplify OPAM pinning for developers
add several functions

- Deferred.Or_error.List: map, iter
- In_thread: run
- Reader: contents, file_contents, file_lines
- Sys: getenv, file_exists
- Unix: getcwd, rename, getpid, and type file_perm