Add more detailed javadoc to Blob and Storage signUrl#743

Merged

mziccard merged 3 commits intogoogleapis:masterfrom mziccard:signurl-javadoc

Mar 15, 2016

+70-11

Commits on Mar 11, 2016

Add more detailed javadoc to Blob and Storage signUrl
mziccard
committed

Commits on Mar 13, 2016

Rephrase signUrl javadoc for better clarity
mziccard
committed

Commits on Mar 15, 2016

Add better javadoc for signUrl examples
mziccard
committed