Aesh should escape special characters

Right now Aesh only escapes space characters. The following characters should be escaped by the aesh completion:

\* ? = ' " { } \ $ ! & ; ( ) < > |

also: TAB-char (yes, I know it is stupid, but possible)

First two (*, ?) are used internally as wildcard chars, so should be allowed to be used escaped as well as unescaped.

Windows has a slightly different set of chars to be escaped (from wikipedia, not actually tested):

' " = & | ( ) < > ^