New practracker exceptions for dependency violations in headers

I've done this manually, since I don't want to override the existing
exceptions in this branch.

scripts/maint/practracker/exceptions.txt

@@ -325,3 +325,12 @@ problem function-size /src/tools/tor-gencert.c:parse_commandline() 111
 problem function-size /src/tools/tor-resolve.c:build_socks5_resolve_request() 102
 problem function-size /src/tools/tor-resolve.c:do_resolve() 171
 problem function-size /src/tools/tor-resolve.c:main() 112
+
+problem dependency-violation /scripts/maint/practracker/testdata/a.c 3
+problem dependency-violation /scripts/maint/practracker/testdata/header.h 3
+problem dependency-violation /src/core/crypto/hs_ntor.h 1
+problem dependency-violation /src/core/or/cell_queue_st.h 1
+problem dependency-violation /src/core/or/channel.h 1
+problem dependency-violation /src/core/or/circuitlist.h 1
+problem dependency-violation /src/core/or/connection_edge.h 1
+problem dependency-violation /src/core/or/or.h 1