Added apply primitive and used it to implement append.
-rw-r--r-- 35142 COPYING
-rw-r--r-- 1217 README.md
-rw-r--r-- 820 debugging.4th
-rw-r--r-- 613 defer-is.4th
-rw-r--r-- 1052 float.4th
-rw-r--r-- 63 launcher.4th
-rw-r--r-- 1098 scheme-library.scm
-rw-r--r-- 7844 scheme-primitives.4th
-rw-r--r-- 30220 scheme.4th
-rw-r--r-- 878 term-colours.4th