Merge in Deans exec summary, ard, dri and lessons learned changes

[deanhintz]

Paragraph added by Dean re extending the data value chain to summarize the general data cube to ARD approach

[deanhintz]

Paragraph added by Dean to exec summary re extending the data value chain to summarize the general data cube to ARD approach

[deanhintz]

also made the following changes to 04-02-ard.adoc: Updated Safe Software Raw Data to ARD section Removed Safe company description - moved to contributors section Removed ARD to DRI sections for drought, heat, flood - to be moved to section 6 ARD to DRI

[deanhintz]

Added Safe Software's heat impact and drought impact DRI component descriptions to this ARD to DRI doc

[deanhintz]

Updated, refined and added new lessons learned from Safe team's experiences.

[deanhintz]

CMIP5 typo correction in dri adoc