Removed unused methods
Removed unused using directives
Try to be more POSIX-y?

`if ! command` appears to be invalid
(https://travis-ci.org/git-tfs/git-tfs/builds/18484621)
Merge pull request #540 from KindDragon/code-cleanup

Code cleanup
Merge pull request #544 from spraints/bashing

Fix script/travis
InitBranch crash on GetRootChangesetForBranch exception fixed
GetRootChangesetForBranch shouldn't download changes, because we use only ChangesetId
nofetch parameter in documentation fixed
LogEntry members reordered

squash! Removed unused methods

squash! LogEntry members reordered
FindCommitHashByChangesetId use compiled regex
Update() fixed for case when file cannot be checkout from TFS
GetRootChangesetForBranch catch VersionControlException
VersionControlException exception handling improved
Init branch crash fixed if branch already exist (big problem with `branch --init --all`)
Better perf by caching branch list

Conflicts:
	GitTfs.VsCommon/TfsHelper.PostVs2010.Common.cs
Ask Tfs server tfs branches only once
Retry on timeout
GetChangesets()  asks changesets by parts
ParseEntries()  called only when really needed
Garbage collection added to `clone` and `branch --all` commands