Correct .str and .long-string directives

Strings produced by the .str and .long-string directives must include
the length of the string as the first word of the string
Correct implementation of .str and .long-string
Add length at the beginning of each string
Re-assemble copied.asm to include string length
Implement Assembler#include
Implement Assembler.include_directive
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Implement CoypDirective class
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Add .fill-array directive to acceptance tests
Add .fill-array output to misc expect-executable
Add newlines to Assembly test input

The input lines to a new Assembly instance have newlines still attached
at the end of the lines.  The Assembly#pop_line  method should chomp
away the newlines.
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