refs: Add `git_referene_target_peel`
refs: Check alloc is cleaner
refs: Do not union the peel
Merge pull request #1475 from libgit2/vmg/refs-peel

Allow access to the cached peel data in packed-refs
repository: Doc fix
use a longer string for dummy data in test to avoid conflicting w/ index
Merge pull request #1478 from ethomson/win32_typechange_test

use a longer string for dummy data in test to avoid conflicting w/ index
Return error for empty name/email
treebuilder: don't overwrite the error message
Merge pull request #1482 from nviennot/error-name-email

Return error for empty name/email