More patches revealed by Eclipse on Jikes RVM

[Julian Dolby]

I have submitted some more patches (1027-1031) based on further work with
Eclipse on Jikes RVM.

patch 1027:  Use the access() syscall provided by Unix to check file
permissions rather than creating temp files

patch 1028: The java.util.zip.InflaterInputStream would crash when asked to
read 0 bytes from the end of a zip file, so I added a check for 0 byte
requests that simply returns 0.

patch 1029: At least read the manifest and call the verify() routine when a
Jar file asks for verification, even though verify() is now a no-op.  This
is needed because some clients assume the manifest has been read initially,
and ask for it after the jar file has been closed meaning it cannot be read
when demanded.

patch 1030:  The java.util.Properties initialization would crash when the
last line the input file ended in \, which normally means more input on
next line.  I made it ignore such final \s.

patch 1031: To make Jikes RVM's life easier, I made the SecurityManager ask
the VMSecurityManager for the current class loaderm rather than trying to
calculate it itself.

      -- Julian