Fix Python<=2.7.6 "TypeError: Struct() argument 1 must be string, not unicode" (#336)

* Fix Python<=2.7.6 "TypeError: Struct() argument 1 must be string, not unicode"

Additional information is available here: http://python-future.org/stdlib_incompatibilities.html#struct-pack

* Completely remove libheap, as it is not ever referenced

pwndbg/arch.py

@@ -60,6 +60,10 @@ def update():
     (8, 'big'):    '>Q',
     }.get((m.ptrsize, m.endian))
 
+    # Work around Python 2.7.6 struct.pack / unicode incompatibility
+    # See https://github.com/pwndbg/pwndbg/pull/336 for more information.
+    m.fmt = str(m.fmt)
+
     # Attempt to detect the qemu-user binary name
     if m.current == 'arm' and m.endian == 'big':
         m.qemu = 'armeb'

pwndbg/commands/search.py

@@ -118,6 +118,10 @@ def search(type, hex, string, executable, writable, value, mapping_name, save, n
             'qword': 'Q'
         }[type]
 
+        # Work around Python 2.7.6 struct.pack / unicode incompatibility
+        # See https://github.com/pwndbg/pwndbg/pull/336 for more information.
+        fmt = str(fmt)
+
         try:
             value = struct.pack(fmt, value)
         except struct.error as e: