Changes to start making the tree use the new memory system. Trying to compile decoder.cc but fails still.

SConscript:
    Place the memory objects back in the right place
arch/alpha/isa_desc:
    Fix includes to point to the new memory requests
cpu/exec_context.hh:
    Exec context now points to memory object, fix the include paths.
    Convert to prot_read/prot_write functions instead of read and write.
    Convert to new CpuRequestPtr instead of MemReqPtr.
mem/request.hh:
    Add back in support for Request Flags (needed by decoder to tag request) Removed the flags that were associated with packets/coherence.
sim/process.hh:
    Converted to point to new memory objects

--HG--
extra : convert_revision : a0b95380915d63b53194e2a26336d6adb1a0086b

SConscript

@@ -44,11 +44,6 @@ Import('env')
 
 # Base sources used by all configurations.
 base_sources = Split('''
-        mem/memory.cc
-        mem/page_table.cc
-        mem/physical.cc
-        mem/proxy.cc
-
 	arch/alpha/decoder.cc
         arch/alpha/alpha_o3_exec.cc
 	arch/alpha/fast_cpu_exec.cc
@@ -131,6 +126,11 @@ base_sources = Split('''
 
 	encumbered/mem/functional/main.cc
 
+        mem/memory.cc
+        mem/page_table.cc
+        mem/physical.cc
+        mem/proxy.cc
+
         python/pyconfig.cc
         python/embedded_py.cc