Update infer to support symlinking

Summary:
While working on building a quick Homebrew formula for this, I ran into symlink-related issues around the libs folder. This seems to fix it with minimal impact.
Closes https://github.com/facebook/infer/pull/13
Github Author: Dan Ambrisco <dambrisco@gmail.com>

Test Plan: Imported from GitHub, without a `Test Plan:` line.

infer/bin/infer

@@ -6,10 +6,10 @@ import inferlib
 import os
 import sys
 
-SCRIPT_FOLDER = os.path.dirname(__file__)
+SCRIPT_FOLDER = os.path.dirname(os.path.realpath(__file__))
 CAPTURE_PACKAGE = 'capture'
 LIB_FOLDER = os.path.join(
-    os.path.dirname(__file__), os.path.pardir, 'lib')
+    os.path.dirname(os.path.realpath(__file__)), os.path.pardir, 'lib')
 
 # token that identifies the end of the options for infer and the beginning
 # of the compilation command