Bug 1036341 - Use the existence of any session files to determine if a profile crashed or is fresh. r=ttaubert

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extra : rebase_source : 15be325a24563254c6d16627cd1de611039356fe
extra : histedit_source : db1e5179d574c0620d446c60848818da14b7ad64%2C6dad046683f375187ca4beda47bea68caa12da9f
Bug 1035557 - Migrate crash checkpoints with the session so that we don't appear to crash during reset. r=ttaubert

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extra : rebase_source : 29fd4cccaf53a4011d8022b733e83eb1d7f25aaf
extra : histedit_source : c0bb058cd59087c126e2462d596f6b72db9d0de1