ASN1 message from S1AP TS 36.413-8a0

To successfully parse messages, the asn1c util should be patched with the patch provided (asn1cpatch.p0).
To do so: 
1) Get the last revision of asn1c: svn co https://asn1c.svn.sourceforge.net/svnroot/asn1c/trunk asn1c
2) Go to asn1c directory
3) patch -p0 asn1cpatch.p0
4) ./configure
5) make
6) make install

Aligned PER support is now included when parsing and generating asn1 code.

To generate S1AP ASN1 descriptions:
Files are automatically generated when changes are made on ASN1 files via Make build system.
