* slightly fix uroboros image.

The body and back were separated by a gap.
* improve Tcl program.

Tcl supports bare string.
* avoid the line-length limit of R.

> Command lines entered at the console are limited to about 4095 bytes
http://cran.r-project.org/doc/manuals/R-intro.html#R-commands_003b-case-sensitivity-etc

To do this, instead of Ruby, Python generates R and REXX.
This also slightly makes intermediate files smaller, but Ruby bigger.
* some improvements for Makefile.

- remove the special handling for Arch Linux (Thanks to @xyproto).
  This closes #22.
- use "logo" instead of "ucblogo" because it looks canonical. (#22)
- check the executable name of Node.js. This closes #18.
- remove the target file when it is failed (.DELETE_ON_ERROR).
  This fixes #14.
* make README.md generation faster.

dpkg is invoked just once.
* use Console.Write instead of WriteLine.

Because it is shorter.
* fix LZW decompressor potential bug.

The first character of compressed string was ignored.
* expand tr.

It is shorter.
* use PR in Logo, which is equivalent to PRINT.
* gain 14 bytes.
* easy compression in Scala.
Shorten check of the executable name of Node.js
Merge pull request #24 from pczarn/archlinux

Using Bash to check the executable name of Node.js
* optionally use `guile` for Scheme.

This closes #26.
Add CHICKEN as a valid scheme
Merge pull request #28 from richo/master

Add CHICKEN as a valid scheme
* update Makefile generator for CHICKEN.

I don't test it, though.
* use gsub instead of scan.map.join.
* remove unused assignment in Java.
* gain 4 bytes.