Bumping gaia.json for 3 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-1_4/rev/111fb65fcff1
Author: Michael Henretty <michael.henretty@gmail.com>
Desc: Merge branch 'v1.4-bug-975535-homescreen' of github.com:samjoch/gaia into samjoch-v1.4-bug-975535-homescreen

Conflicts:
	external-apps/marketplace.firefox.com/application.zip

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https://hg.mozilla.org/integration/gaia-1_4/rev/3a3f6cc90b77
Author: Amir Nissim <amirnissim@gmail.com>
Desc: Bug 975535 - E.me followups [r=ranbena]

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https://hg.mozilla.org/integration/gaia-1_4/rev/89052e1a5f8a
Author: Sam Joch <samuel@guiora.com>
Desc: Bug 975535 - [VsD Refresh] Update App Icons in Homescreen & Settings/App Permissions
Bumping manifests a=b2g-bump