Rename gprs_rlcmac_ts_alloc.cpp -> alloc_algo.cpp & create own .h file

First commit towards trying to have alloc algorithm as isolated as
possible from others parts of the code trying to avoid state changes on
data structures.
Change name also because the alloc_algo not only allocated TS, but TFIs
and USFs.

Change-Id: I33a6c178c64a769f05d3880a69c38acb154afa62
diff --git a/tests/app_info/AppInfoTest.cpp b/tests/app_info/AppInfoTest.cpp
index 6806f20..668b081 100644
--- a/tests/app_info/AppInfoTest.cpp
+++ b/tests/app_info/AppInfoTest.cpp
@@ -24,6 +24,8 @@
 #include <osmocom/core/utils.h>
 #include <osmocom/core/msgb.h>
 #include <osmocom/core/application.h>
+
+#include "alloc_algo.h"
 }
 
 using namespace std;