Compile the HTML docs using charset UTF-8.
Use Archimedes instead of Gnuplot for the "mem" example.
Improve indentation.
Improve basic test.
Ensure no OCaml value is accessed when releasing the master lock.
Fix dimensions checks.
Synchronize the doc and code about preserve_input default value.
Use destroy_input instead of preserve_input.

The idea is to emphasize that the default is "preserve_input": the
option has an effect only if it is explicitly activated.
Remove destroy_input to c2r 2D and 3D.

The FFTW manual says "for multi-dimensional c2r transforms, however,
no input-preserving algorithms are implemented and the planner will
return NULL if one is requested"; thus there is no point in allowing
to set this option.
Version OPAM file.
Add make target to create an opam dir.
Version 0.7