Removed old `yieldIf` code from `filter` documentation
Changed residual `printN`s in the tutorial to `stdout`
Merge branch 'master' of github.com:Gabriel439/Haskell-Pipes-Library
Added constructor analogs of all the `runXXXP` functions

This fixes #72.  I went beyond the original request to include `readerP`,
`writerP`, `stateP`, and `rwsP` "smart constructors".
Fixed documentation for `errorP` and `runErrorP`
Removed `foldl` dependency

I decided to remove the `foldl` dependency for a few reasons:

* Writing custom folds required importing `Control.Foldl`

* It was an extra dependency

* `foldl` is probably going to be unstable in the near future

I made sure all the folds in `Pipes.Prelude` can still accept the fields of
a `Fold` or `FoldM` type.

It is more likely that I will make `foldl` depend on `pipes` to provide
`Fold` integration for `pipes`.
Added note to `Pipes.Prelude` documentation

This explains that `stdin` and `stdout` remove and add newlines so that users
are not confused when they transition to `Text` and `ByteString` utilities.  See
issue #71.
Add Prelude.concat and Prelude.mapM benchmarks.

Change function supplied to Prelude.map.
Merge pull request #65 from archblob/benchmarks

Add Prelude.concat and Prelude.mapM benchmarks.
Updated documentation
Updated documentation
Merge branch 'master' of github.com:Gabriel439/Haskell-Pipes-Library
Migrated `run` to `Pipes.Prelude` and replaced it with `runEffect`

This was done for consistency with other monad transformers.  The old run
is still in `Pipes.Prelude` for people who find `runEffect` too verbose.
Fixed `README.md` to use `runEffect`
Moved `liftCatchError` source back to `Pipes.Lift`
Merge branch 'master' of github.com:Gabriel439/Haskell-Pipes-Library
Removed 'run' from `Pipes.Prelude`

This is based on a suggestion from @k0001 that it's better not to have a
redundant function in order to improve the readability of `pipes` code, so I
decided to pick `runEffect`.
Fixed some minor errors in the tutorial code examples
Added community-contributed libraries to the README
Polished tutorial