Eliminate failure returns from _dl_split_path(): if malloc fails just _dl_oom()
Prompted by Qualys's leveraging malloc failure in _dl_split_path() to get
stuff past.

ok deraadt@ millert@

Do not interpret an empty path as current working directory "." when
parsing LD_LIBRARY_PATH, and in DT_RPATH and DT_RUNPATH attributes and
in ld.so.hints.

ok deraadt@

be pedantic with sizeof use
no change in behaviour as sizeof(char **) is the same as sizeof(char *)
ok otto@ guenther@

delete annoying white space that annoy

<sys/param.h> to <limits.h> conversion. Verified binaries
ok millert, thanks to doug for process advice

check all memory allocations; ok miod@ guenther@

Move to a non-zeroing _dl_malloc, a _dl_calloc and _dl_reallocarry and
fix _dl_strdup to return NULL instead of crash; ok deraadt@

- Parse colon separated paths into NULL terminated arrays of string
pointers to prepare for adding rpath ORIGIN support.
okay matthew@ millert@