[FIX] sap.m.MultiCombobox: Missing Placeholders in IE10

- Increasing the z-index of the "simulated" placeholder of the InputBase
solves that problem.
- Fixes also the problem with placeholders inside the MultiInput.
- cherry picked from commit aca1c65d32ba1c542be90062f8670e20e86968aa)

Change-Id: I6412d979de25f0876f667ad063c12c606306b0d4
BCP: 1482007105
CR-Id: 012003146900009269762014
[FIX] sap.m.UploadCollection: replacement of 'internet_explorer' with
'msie'

CR-Id: 012003146900009371072014
Change-Id: I0e0bdd9a38d9dab8a08959e026a3612a7594b881
Merge "[FIX] sap.m.MultiCombobox: Missing Placeholders in IE10" into rel-1.26
Merge "[FIX] sap.m.UploadCollection: replacement of 'internet_explorer' with 'msie'" into rel-1.26