make install uses user's umask

[John Foerch]

I encountered the following problem with 'make install' with chicken 4.8.0:

My umask is 027, which means that by default, new files that I create have no permission bits set for 'other'.

I installed chicken like this:

$ sudo make PLATFORM=linux install

I found that the installed files had used my umask instead of a sane default. The directories /usr/local/include/chicken and /usr/local/lib/chicken/ (and maybe others?) had no permission bits set for other.

[sjamaan]

I think this should be trivial to fix, so let's try to do it for 4.9.0

[sjamaan]

Fixed by 37a788c