bump version to 2.3.8

Add tclstub support (flightaware#23)

* Add tclstub support

Initialize the stubs when needed.

* Bump version

* Add tclstub support

To build with tclstub library run.
You have to autogen.sh to create a fresh configure.

NOCONFIGURE=1 ./autogen.sh
./configure --enable-tclstub

And add any other flags you need.

We ship the configure script to help distro's that do not
run a full autogen.sh. But stubs is only available if you
run autogen.sh (or the automake process).

Rebuild configure

Update version number.

Remove configure from .gitignore and add to repo.

Commit a Linux configure and autotools environment.

increment version to 2.3.2

libtool cannot be missing on Travis-CI

Merging devel to master (flightaware#3)

* Create .travis.yml

* Add development dependencies

* Remove enable-maintainer-mode

* Fix include path detection

Use the TCL_INCLUDE_SPEC variable from tclConfig.sh to find tcl.h

* Save after every history addition. (flightaware#2)

* Save after every history addition.

* Make autosave optional and off by default.

* Document autosave in the sample tclshrc

* Be nicer to the end user and accept anything boolean looking for autosave

add autoconf stuff put in by libtoolize et al