Simplify some make rules
Simplify some make rules

A rule of type "a/%: a/%.in" will also match "a/b/%: a/b/%.in", so no
need for the explicit examples/hooks rule. As for the man rules, they
are identical and thus can be collapsed.

We still have the problem that globally, not all our %.in to %
transformations are identical; this is suboptimal and should be
cleaned sometime…

Signed-off-by: Iustin Pop <acf83a5274f31a43af6b914614365999469c1a31@google.com>
Reviewed-by: Guido Trotter <f62ca4d5358bdaeef0e50e57f9f7e231de63727e@google.com>

grnet/snf-ganeti,apyrgio/snf-ganeti,yiannist/ganeti,dimara/ganeti,mbakke/ganeti,apyrgio/ganeti,mbakke/ganeti,dimara/ganeti,andir/ganeti,leshchevds/ganeti,andir/ganeti,ganeti/ganeti,bitemyapp/ganeti,andir/ganeti,onponomarev/ganeti,yiannist/ganeti,ganeti-github-testing/ganeti-test-1,apyrgio/snf-ganeti,leshchevds/ganeti,ganeti/ganeti,onponomarev/ganeti,ganeti/ganeti,yiannist/ganeti,mbakke/ganeti,grnet/snf-ganeti,leshchevds/ganeti,apyrgio/ganeti,ganeti-github-testing/ganeti-test-1,bitemyapp/ganeti