hopefully last Makefile mash-up
Tweaked Makefile a bit:
 You can set where it should install Sparkling using DESTDIR
 spn.o & spn executable are no longer built in the current dir
 It now fully respects the $(OBJDIR) setting
Merge pull request #2 from sfan5/patch1

Tweaked Makefile a bit
Merge branch 'master' of github.com:H2CO3/Sparkling
fixed broken build system once again
exit() now works without an argument; assumes successful termination
clarified semantics of arrays as function argument
spelling; array iterators; convenience context API; minor fixes
grammar; date
fixed binary file mode on Windows; removed trailing whitespace
removed implicit self and other unused parts; new math functions; negative literals; minor improvements
corrected parsing functions; removed an obsolete comment
unified Makefile; control showing nil values; getline() handles EOF correctly
function call stack trace
array subscript operator [] now handles strings too
removed logo image
reorganized lexer/parser headers to fix cross-reference
handle error messages properly
added format strings
various fixes, documentation, typos, etc.