Makefile.in: Convert to ./ throughout.

* Makefile.in: Convert to ./ throughout.  Rebuild dependencies
with explicit build rules.
(VPATH): Remove.
(.c.o): Poison.
* configure.ac (pexecute, LIBOBJS): Add ./ .
* maint-tool: Build dependencies with explicit rules.

From-SVN: r76366
diff --git a/libiberty/getpwd.c b/libiberty/getpwd.c
index f508b1e..31c7d20 100644
--- a/libiberty/getpwd.c
+++ b/libiberty/getpwd.c
@@ -35,6 +35,9 @@
 #if HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
+#if HAVE_LIMITS_H
+#include <limits.h>
+#endif
 
 /* Prototype these in case the system headers don't provide them. */
 extern char *getpwd ();