Extend memory value declaration syntax in config file

[phil777]

Make it possible to use quoted strings, if possible with escapes, and that can be concatenated with ||

mem[0x10000] = "my string"
mem[0x20000] = "my string terminated with zero\x00"
mem[0x30000] = "my string terminated with zero too"|00|
mem[0x40000] = "abcd"|646566|"efgh\x00"

Also make it possible to add !all to taint the whole memory zone.