Merge branch 'master' into issue10

The echo shell builtin of the traditional Bourne Shell does not recognize the
-e option. Better use printf in this case.

From the POSIX manual for printf:

RATIONALE
  The printf utility was added to provide functionality that has histori-
  cally been provided by echo. However, due to irreconcilable differ-
  ences in the various versions of echo extant, the version has few special
  features, leaving those to this new printf utility, which is based on one in
  the Ninth Edition system.

End-user documentation for lisousi shall be improved on this branch.
Add a step-by-step example for the sparse receiver array example, testcase
Bietigheim.

compile.sh will not execute in traditional Bourne Shell. Explicitely request a
version of the Bourne Again Shell.

the fixed wavelet engine ist not yet implemented

After implementation of full usage information for end-users and ouput of
usage texts in soutifu, modifications are merged into master.

A comprehensible textual description of what actually is done in the procude
is still missing.

The weight factors are applied in terms of signal amplitude not in terms of
signal energy. Where factors are to be applied to energy values, they have to
be squared prior to the operation.

weight factor is defined in terms amplitude; apply square of weight to signal
energy

The compound information is composed from different sources but must be
reasonable as a whole.

The usage text strings already contain a terminal newline.

All usage output function calls are implemented. Texts are still missing.

- library usage function implementation ist still incomplete

Implement a new set and hierarchy of end-user usage functions:
- engines: prints a list of available procedures
- help: prints the list of procedures together with a brief usage summary
- usage: prints the detailed description for the selected procedure

Function declarations are provided. onlinehelp.cc addresses these new
functions. Function bodies, however, are not yet implemented.

Next:
- implement bodies of usage and classusage functions.
- adjust bodies of implemented classhelp functions.
- new bodies must make use of character strings created automatically
  from *usage.txt files

C API does not require a specific usage information for end-users.

Not only for doxygen it is helpful to keep usage text files in a separate
directory.