- need to trap possibly weird input within etc/bashrc, etc/cshrc and
  can't easily redirect stderr in csh.

- renamed clearEnv -> unset

- avoid editing of settings.{sh,csh}

- alternative to WM_PROJECT_INST_DIR/site for systems with locked down
  installation paths (eg, when packaged as RPM or deb)

  When "$WM_PROJECT_SITE" is defined, it is used in favour of
  "$WM_PROJECT_INST_DIR/site"

- can be reused for other (vector, tensor, ...) field types

- prevented the reloading from working properly (thanks Mattijs!)

- useful for debugging purposes

Problems remain with codedFixedValueFvPatchScalarField:

- readIfModified() notices change on system/codeDict, but the
  codeProperties::setUnmodified() means that only a single entry will
  get processed

- it appears that while dlclose() may (or may not) be actually closing
  the library, there are probably still references about. This means
  that a subsequent reloading still points to the original functions
  and the lookup is not updated correctly.

- use newly introduced makeRemovablePatchTypeField to avoid this problem

- eg, fixedValue10_<SHA1>, its existence indicates that the correct
  library has been loaded

- add doc-dir doc/doxygen so it doesn't get forgotten

- write intermediate code to _SHA1 directories
- add Test-codeStream