java/jlint: Fix build with Clang 6

In file included from access_desc.cc:1:
In file included from ./access_desc.hh:8:
In file included from ./class_desc.hh:4:
./types.hh:144:6: error: constant expression evaluates to 4294967168 which cannot be narrowed to type 'int4' (aka 'int') [-Wc++11-narrowing]

{0xffffff80, 0x0000007f}, // tp_byte
 ^~~~~~~~~~

http://beefy11.nyi.freebsd.org/data/head-i386-default/p478276_s338342/logs/errors/jlint-3.1.2_4.log

jlint.cc:1044:33: error: no matching literal operator for call to 'operator""DATE' with arguments of types 'const char *' and 'unsigned long', and no matching literal operator template

"version %s ("__DATE__").\n", VERSION);
              ^

• Remove embedded build date
• Make sure the build respects CXXFLAGS, LDFLAGS, LIBS