Add datetime log in Omnisharp Log

[jchannon]

Environment data

dotnet --info output:

.NET Command Line Tools (1.0.0-preview2-003121)

Product Information:
 Version:            1.0.0-preview2-003121
 Commit SHA-1 hash:  1e9d529bc5

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  10.11
 OS Platform: Darwin
 RID:         osx.10.11-x64

VS Code version: 1.3
C# Extension version: 1.2.2

Steps to reproduce

Open a solution with Omnisharp

Change git branches

Restart Omnisharp

View Omnisharp Logs

Expected behavior

In Omnisharp Logs see a datetime against the log entries to see which solution loading it refers to

Actual behavior

No datetime against log entries