ShellPkg: CTRL-C stops a running script at the same time

This makes CTRL-C stop a running script after trying to stop the command.  And adds comments to describe the behavior more clearly.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Erik Bjorge <erik.c.bjorge@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15008 6f19259b-4bc3-4df7-8a09-765794883524
ShellPkg: fix whitespace character trimming

This makes TrimSpaces() trim tab characters off the end of the string also (not just the beginning).  Also updates loop to prevent buffer underrun.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Erik Bjorge <erik.c.bjorge@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15009 6f19259b-4bc3-4df7-8a09-765794883524
ShellPkg: API name typo.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jaben Carsey <jaben.carsey@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15010 6f19259b-4bc3-4df7-8a09-765794883524
ShellPkg: pre-verify split commands

This makes sure that all parts of commands split via pipe operation are valid before starting.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jaben Carsey <jaben.carsey@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15011 6f19259b-4bc3-4df7-8a09-765794883524