src: use include/osmocom/abis instead of include/osmocom/gsm/abis

Harald prefers short paths.

This patch also remove commented includes in several files.
diff --git a/include/osmocom/Makefile.am b/include/osmocom/Makefile.am
index 999a3ee..f9d5e7c 100644
--- a/include/osmocom/Makefile.am
+++ b/include/osmocom/Makefile.am
@@ -1 +1 @@
-SUBDIRS=gsm
+SUBDIRS=abis
diff --git a/include/osmocom/gsm/abis/Makefile.am b/include/osmocom/abis/Makefile.am
similarity index 100%
rename from include/osmocom/gsm/abis/Makefile.am
rename to include/osmocom/abis/Makefile.am
diff --git a/include/osmocom/gsm/abis/e1_input.h b/include/osmocom/abis/e1_input.h
similarity index 98%
rename from include/osmocom/gsm/abis/e1_input.h
rename to include/osmocom/abis/e1_input.h
index 1911568..c5a4137 100644
--- a/include/osmocom/gsm/abis/e1_input.h
+++ b/include/osmocom/abis/e1_input.h
@@ -5,11 +5,10 @@
 #include <netinet/in.h>
 
 #include <osmocom/core/linuxlist.h>
-//#include <openbsc/gsm_data.h>
 #include <osmocom/core/timer.h>
 #include <osmocom/core/msgb.h>
 #include <osmocom/core/select.h>
-#include <osmocom/gsm/abis/subchan_demux.h>
+#include <osmocom/abis/subchan_demux.h>
 
 #define NUM_E1_TS   32
 
diff --git a/include/osmocom/gsm/abis/ipaccess.h b/include/osmocom/abis/ipaccess.h
similarity index 100%
rename from include/osmocom/gsm/abis/ipaccess.h
rename to include/osmocom/abis/ipaccess.h
diff --git a/include/osmocom/gsm/abis/subchan_demux.h b/include/osmocom/abis/subchan_demux.h
similarity index 100%
rename from include/osmocom/gsm/abis/subchan_demux.h
rename to include/osmocom/abis/subchan_demux.h
diff --git a/include/osmocom/gsm/abis/trau_frame.h b/include/osmocom/abis/trau_frame.h
similarity index 100%
rename from include/osmocom/gsm/abis/trau_frame.h
rename to include/osmocom/abis/trau_frame.h
diff --git a/include/osmocom/gsm/Makefile.am b/include/osmocom/gsm/Makefile.am
deleted file mode 100644
index f9d5e7c..0000000
--- a/include/osmocom/gsm/Makefile.am
+++ /dev/null
@@ -1 +0,0 @@
-SUBDIRS=abis