Check CPU architecture in defines.sh to download correct eclipse version

The current script always downloads the x86_64 version of eclipse. The
script in this commit checks whether the architecture is 32 or 64 bit
and downloads the correct eclipse version.
Adds support for 32 build servers

This commit extends 6128f84330c1bd5efea187f7ff477b53e0b7e32e to
complete support for 32 bit Linux servers for generating nightly orcc
builds.

1. The download of p2-admin is now sensitive to 32/64 bit
   architecture.

2. build.properties in pdeconfig now builds for both x86 and x86_64.
Merge pull request #5 from robstewart57/master

Check CPU architecture in defines.sh to download correct eclipse version