#485 (Apr 27, 2021, 6:14:55 PM)

PR #1543: Linkedfn fixes

	Changes linked fns warn if not united, allow substitutions for linked vecfns (commit: 8122939) (details / githubweb) small fixes (commit: 353cb75) (details / githubweb) addd test (commit: 9bb3990) (details / githubweb) only add gradients if there's truthy tags (commit: 7f95279) (details / githubweb)
	GitHub pull request #1543 of commit 7f952791499fa43fb4a50e421042849081c20766, no merge conflicts.
	SCM: git https://github.com/convexengineering/gpkit Commits since last build: 200 Latest commit: 8d3a427
	Test Result (3 failures / -31) gpkit.tests.from_paths.TestFiles.test_solar_sens_chart_py_mosek_cli gpkit.tests.from_paths.TestFiles.test_solar_sens_chart_py_mosek_conif gpkit.tests.from_paths.TestFiles.test_model_jho_py_mosek_conif