lib: Rearchitect trace file parsing to use GDataInputStream
lib: Rearchitect trace file parsing to use GDataInputStream

Use GDataInputStream rather than a home-grown buffering solution which
broke if the string it was searching for (‘\n> ’ or ‘\n< ’) was split
over a 1024 byte boundary.

pwithnall/uhttpmock,Distrotech/uhttpmock,MathieuDuponchelle/uhttpmock,MathieuDuponchelle/uhttpmock,Distrotech/uhttpmock,pwithnall/uhttpmock,MathieuDuponchelle/uhttpmock