cve-log: one 'stable' fix can point to several upstream commits

See 143d9963df6580491f9a5c38c9d4883786f78123
cve-log: fix -n<num> option

this was broken by commit 6b75f4f90ef4ac89598940eb53e0e880666dbee7

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
workaround a bug in bash 4.2: trap handlers are not called in 'subshell1 | subshell2' construct

For example in:

 { trap "echo EXIT handler called" EXIT; echo done; } | cat

the exit handler is not called. To fix it, I had to do instead:

 ( trap "echo EXIT handler called" EXIT; echo done; ) | cat
cve-log: use git-merge-base to find master and positive sets boundaries

Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>