Add installation instructions, make the install target work without man pages
Allow install/uninstall without man page
Add install, uninstall, and package targets. Closes #17
Rename strdup to my_strdup

I'm not sure how to make this so that if strdup is provided, it's used,
but otherwise it's not.
Portable Makefile

* Use Makefile.conf to specify options
* No obj/ dir (to facilitate Makefile suffix rules), build objects in
  the source tree
Merge branch 'feature/c89_pedantic', closes #4
Fix warnings in tools files
Silence errors in src/types.c
Silence warnings in src/iter.c
fix warnings in src/builtins.c
Fix warnings in src/parse.c
Fix warnings in src/util.c
Fix warnings in src/hashtable.c
Fix warnings in src/ringbuf.c
Fix all warnings in src/gc.c
Add -pedantic to CFLAGS
Nicer frontpages
Use const unsigned long for hash table sizes, closes #15
Merge branch 'feature/error_handling', closes #12