Update 45.7.0

Security fixes:
#CVE-2017-5375: Excessive JIT code allocation allows bypass of ASLR and DEP
#CVE-2017-5376: Use-after-free in XSL
#CVE-2017-5378: Pointer and frame data leakage of Javascript objects
#CVE-2017-5380: Potential use-after-free during DOM manipulations
#CVE-2017-5390: Insecure communication methods in Developer Tools JSON viewer
#CVE-2017-5396: Use-after-free with Media Decoder
#CVE-2017-5383: Location bar spoofing with unicode characters
#CVE-2017-5386: WebExtensions can use data: protocol to affect other extensions
#CVE-2017-5373: Memory safety bugs fixed in Firefox 51 and Firefox ESR 45.7

(ryoon)