Many TEA based Tcl extensions have need of a config or tclconfig directory that isn't found in the sampleextension which is the basis for a TEA extension.
tclconfig is found in the tclconfig fossil repository at http://core.tcl.tk/tclconfig (2013-06-28: Link appears to be non-functional). It contains some TEA specific files which typically reside in the tclconfig subdirectory of a Tcl extension. Copy them into that directory if you need to create an extension with autoconf.
Note that this directory is not directly related to tclConfig.sh , however, both are a part of the Tcl Extension Architecture.
old tclconfig description when Tcl was still maintained on sourceforgeMany TEA based Tcl extensions, when found in a CVS such as one finds at SourceForge, have need of a config or tclconfig directory that isn't found in the CVS.
The contents of this directory can be found in the sampleextension module that is a part of http://tcl.sf.net/ . It contains some TEA specific files.