(MAINT) Copy-edited all the user-visible messages

[jbondpdx]

Edited strings for readability and consistency.

[coveralls]

Coverage decreased (-0.4%) to 93.249% when pulling 29431f1 on jbondpdx:string-edits into c961bed on puppetlabs:master.

[coveralls]

Coverage decreased (-0.4%) to 93.249% when pulling 5d4b3cc on jbondpdx:string-edits into c961bed on puppetlabs:master.

[coveralls]

Coverage remained the same at 93.691% when pulling bf2c922 on jbondpdx:string-edits into c961bed on puppetlabs:master.

[coveralls]

Coverage increased (+0.02%) to 93.707% when pulling d312f03 on jbondpdx:string-edits into c961bed on puppetlabs:master.

[coveralls]

Coverage decreased (-0.2%) to 93.518% when pulling 8dd72f0 on jbondpdx:string-edits into c961bed on puppetlabs:master.

[coveralls]

Coverage increased (+0.02%) to 93.707% when pulling 2dd8a47 on jbondpdx:string-edits into c961bed on puppetlabs:master.