FIX: fix_version enumeration ordering
FIX: fix_version enumeration ordering

Make "enum fix_version" enumeration ordered by protocol versions in
ascending order so that you can use comparison operators for version
specific logic.

NOTE! This breaks ABI compatibility for applications built against older
versions of libtrading.

Signed-off-by: Pekka Enberg <add4fcd06328a394f0ad91feda7ee057316dc5ed@iki.fi>

femtotrader/libtrading,jvirtanen/libtrading,NunoEdgarGub1/libtrading,mstanichenko/libtrading,etoestja/libtrading,jvirtanen/libtrading,libtrading/libtrading,penberg/libtrading,svdev/libtrading,libtrading/libtrading,etoestja/libtrading,mstanichenko/libtrading,NunoEdgarGub1/libtrading,penberg/libtrading,fengzhyuan/libtrading,divaykin/libtrading,femtotrader/libtrading,svdev/libtrading,divaykin/libtrading,fengzhyuan/libtrading