Since $() command substitution already is specific to bash and not available
in standard Bourne Shell, replace shell in which shell scripts shall be
executed by /bin/bash.

On this branch issue14 will be resolved:

do not rely on /bin/bash
------------------------

Parts of the project rely on /bin/bash being the standard shell and /bin/sh
being a synonym for /bin/bash.

 *  This is the case in shell scripts, which use bash-specific commands and
    keywords.
 *  This is the case in Makefiles, which use constructs like 'echo -e' to
    format multiline string output.

The problem can be solved by:

 *  replacing '#!/bin/sh' by '#!/bin/bash' in shell scripts
 *  replacing 'echo -e' by 'printf' in Makefiles

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.

copy texts from output of onlinehelp to ASCII text files.

onlinehelp.xxx will be replaced by the newly provided ASCII text files which
contain usage information for end-users.

package targets are no longer required, since gitlab provides access to
snapshot targets. Package creation is no longer supported for Seitosh.

The output of end-user information must be organized within the library. The
library will provide only two ways to access end-user usage information:

1. A complete display of all summary usage texts.
2. A selected detailed usage description for an operational engine selected by
   its ID together with detailed information for the general library and
   detailed description of the base classes, if there are any.

Calls to output functions must pass execution in the appropriate order to
select usage texts for output in a meaningful order.