Convert the exported items in virsh.h to use a common 'vsh' prefix.

* tools/virsh.h (VIRSH_MAX_XML_FILE): Rename...
(VSH_MAX_XML_FILE): ...and parenthesize.
(DIFF_MSEC, CTRL_CLOSE_BRACKET): Delete.
(vshUsage, vshInit, vshDeinit, vshParseArgv): Remove prototype.
(editWriteToTempFile, editFile, editReadBackFile, prettyCapacity)
(virshReportError): Rename...
(vshEditWriteToTempFile, vshEditFile, vshEditReadBackFile)
(vshPrettyCapacity, vshReportError): ...into vsh namespace.
(jobWatchTimeoutFunc): Move to virsh-domain.c.
* tools/virsh.c (vshCommandRun): Inline former DIFF_MSEC.
(main): Inline former CTRL_CLOSE_BRACKET.
(vshUsage, vshInit, vshDeinit, vshParseArgv): Make static.
(prettyCapacity, virshReportError, editWriteToTempFile, editFile):
Fix naming, and adjust usage.
(vshAskReedit, vshCommandRun, vshEventLoop, vshInit): Adjust
usage.
* tools/virsh-domain.c (cmdAttachDevice, cmdCPUCompare)
(cmdCPUBaseline, cmdCreate, cmdDefine, cmdDetachDevice)
(cmdUpdateDevice, cmdDesc, cmdUndefine, cmdStart, cmdVcpucount)
(cmdAttachDevice, cmdDomjobinfo): Likewise.
* tools/virsh-edit.c (do): Likewise.
* tools/virsh-interface.c (cmdInterfaceDefine): Likewise.
* tools/virsh-network.c (cmdNetworkCreate, cmdNetworkDefine):
Likewise.
* tools/virsh-nodedev.c (cmdNodeDeviceCreate): Likewise.
* tools/virsh-nwfilter.c (cmdNWFilterDefine): Likewise.
* tools/virsh-pool.c (cmdPoolCreate, cmdPoolDefine)
(cmdPoolDiscoverSources, cmdPoolList): Likewise.
* tools/virsh-secret.c (cmdSecretDefine): Likewise.
* tools/virsh-snapshot.c (cmdSnapshotCreate, vshSnapshotCreate)
(vshLookupSnapshot, cmdSnapshotEdit, cmdSnapshotCurrent)
(vshGetSnapshotParent): Likewise.
* tools/virsh-volume.c (cmdVolCreate, cmdVolCreateFrom)
(cmdVolInfo, cmdVolList): Likewise.