Allow the .SHELL target to specify the list of shell meta characters and the list of shell builtins. Both of these are needed for the compat mode where make directly executes commands if the command line contains neither a shell meta character nor a shell builtin. The list of builtins is not changed, but csh has '@' added as a meta-character.
Allow the .SHELL target to specify the list of shell meta characters and
the list of shell builtins. Both of these are needed for the compat
mode where make directly executes commands if the command line contains
neither a shell meta character nor a shell builtin. The list of builtins
is not changed, but csh has '@' added as a meta-character.

Initialize the default shell by parsing a string as one would specify
to the .SHELL target. So we get rid of the CShell clone of struct Shell which
just contained const char * where struct Shell had char *.

Add a debugging function for dumping a parsed shell description to
stdout.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase