Delete OMERO tools build info (rebased onto dev_5_0)



This is the same as gh-958 but rebased onto dev_5_0.

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See https://trello.com/c/xXDGSsya/189-truncated-sentence-in-build-system-html - Simon reported missing info and on further examination, Roger declared this confusing and out-of-date anyway.

There is a card for a proper review of this page (https://trello.com/c/YsNGqtHn/165-review-http-www-openmicroscopy-org-site-support-omero5-developers-build-system-html) but that will have to wait until @joshmoore has time to look at it by the sounds of things.