grammar/English; naming conventions; removed some obsolete functions
fixed a memory management bug in SPN_INS_ARRGET; removed static variables
added custom error messages for native functions
this should pay attention to custom error messages as well
longjmp() is evil; native functions are shown in stack trace
fixed a memory leak in REPL
so that function calls won't result in crazy mallocation
added some safety to format strings
added some safety to format strings
reorganized API; fixed a bug in AST dumps; various minor fixes
GCC is sometimes dumb
don't get confused by 0-byte text files
fix leaked file descriptor; improved error messages from C-land
Even more API clean-up

Added "modules" and some context APIs

improved documentation, TODO, English

fixed the hack in the compiler
amended C function handling; safety improvements; updated documentation
changed foreach; updated documentation and examples
Safety improvements in compiler; improved Makefile (better cross-platform builds, dynamic library)

spn_vm_callfunc and spn_vm_exec clean up automatically

initializing a variable with itself yields nil
fixed typos and a misconception
added `global` keyword; renamed fmtstring()
re-thought value API; minor fixes