Fix unicode crash installing activate script
Fix unicode crash installing activate script

... home_dir is (at least in some case) a byte string and is being
inserted into a unicode string; this explicitly uses the filesystem
encoding to do so (else the ascii encoding gets used by default, which
fails if the path contains non-ASCII characters).

dstufft/virtualenv,haridsv/virtualenv,madprog/virtualenv,kissthink/virtualenv,vvtam/virtualenv,francatore/virtualenv,bigplus/virtualenv,blueyed/virtualenv,techtonik/virtualenv,mykemunson/virtualenv,mykemunson/virtualenv,francatore/virtualenv,ionelmc/virtualenv,davidszotten/virtualenv,dstufft/virtualenv,madprog/virtualenv,vvtam/virtualenv,msabramo/virtualenv,davidszotten/virtualenv,ionelmc/virtualenv,Ivoz/virtualenv,msabramo/virtualenv,ionelmc/virtualenv,Seha16/virtualenv,jedie/virtualenv,jedie/virtualenv,msabramo/virtualenv,bigplus/virtualenv,blueyed/virtualenv,Ivoz/virtualenv,RAS-ViVa/virtualenv,RAS-ViVa/virtualenv,Seha16/virtualenv,techtonik/virtualenv,Lyleo/virtualenv,haridsv/virtualenv,Lyleo/virtualenv,kissthink/virtualenv