OSPFd: Update Segment Routing PR following review

OSPFd: Update Segment Routing PR following review

Following various review, following files have been modfied:

 - All: Change u_intXX_t typedef to standard uintXX_t types
 - doc/OSPF-SR.rst: Update doc in particular the Linux Kernel configuration
section
 - doc/ospfd.texi: Update CLI
 - ospfd/ospf_dump.[c,h]: Add new 'debug ospf sr' when performing 'sh run'
 - ospfd/ospf_ext.[c, h]: Various bug corrections notably to handle flooding of
Extended Prefix at startup. iFix TLVs size for LAN Adjacency.
Update Licence as per Community.md
 - ospfd/ospf_opaque.c: Add proper termination function call to remove MPLS entries
 - ospfd/ospf_ri.[c,h]: Bug corrections
 - ospfd/ospf_sr.[c,h]: Various bug corrections, notably to determine the nexthop
SR Node. Add support to 'no-php-flag'.
Update Licence as per Community.md
 - ospfd/ospfd.c: Add call to 'ospf_opaque_term()'

Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>