Fast haar transform algorithm

Needs rework
1) Change name to {inverseH,h}aarTransform
2) Rename helpers to Can{Inverse,}HaarTransform
3) Add unit tests
Rename "fht" to "haarTransform"
Rename inverseHaarTransform
Add test for 1d haar transform
fliplr/flipud/rot90
remove an unused implicit providing trait
clip(a, low, high) forces values in a to be in the range [low, high]
Merge branch 'master' of github.com:dlwh/breeze

Conflicts:
	src/test/scala/breeze/linalg/DenseVectorTest.scala
de-expanding reverse.
Merge branch 'filter1'
don't need this file.
Merge branch 'fast-haar-transform' of github.com:rtreffer/breeze into rtreffer

Conflicts:
	src/main/scala/breeze/signal/package.scala
allow reshaping of empty matrices.
Merge branch 'master' of github.com:dlwh/breeze
Merge branch 'filter1' of github.com:ktakagaki/breeze

Conflicts:
	src/main/scala/breeze/signal/package.scala
	src/main/scala/breeze/signal/support/CanFilterXX.scala
fix the rather embarrassing #143
Merge branch 'master' of github.com:dlwh/breeze
manually expanding some fft implicits because scaladoc is breaking.
Merge remote-tracking branch 'scalanlp/master'
Merge branch 'master' into Constants